pMJFORNIA
FISH-GAME
VOLUME 46
JULY, 1960
NUMBER 3
California Fish and Game is o journal devoted to the conserva-
tion of wildlife. Its contents may be reproduced elsewhere pro-
vided credit is given the authors and the California Department
of Fish and Game.
The free mailing list Is limited by budgetary considerations to
persons who con make professional use of the material and
to libraries, scientific institutions, and conservation agencies. Indi-
viduals must state their affiliation and position when submitting
their applications. Subscriptions must be renewed annually by
returning the postcard enclosed with each October issue. Sub-
scribers are asked to report changes in address without delay.
Please direct correspondence to:
CAROL M. FERREL, Edifor
Department of Fish and Game
722 Capitol Avenue
Sacramento 14, California
Individuals and organizations who do not qualify for the free
mailing list may subscribe at a rate or $2 per year or obtain indi-
vidual issues for $0.75 per copy by placing their orders with the
Printing Division, Documents Section, Sacramento 14, California.
Money orders or checks should be made out to Printing Division,
Documents Section.
u
I]
V
VOLUME 46
JULY, 1960
NUMBER 3
Published Quarterly by the
CALIFORNIA DEPARTMENT OF FISH AND GAME
SACRAMENTO
STATE OF CALIFORNIA
DEPARTMENT OF FISH AND GAME
EDMUND G. BROWN
Governor
FISH AND GAME COMMISSION
WILLIAM P. ELSER, President
San Diego
JAMIE H. SMITH, Vice President T. H. RICHARDS, JR., Commissioner
Los Angeles Sacramento
CARL F. WENTE, Commissioner HENRY CLINESCHMIDT, Commissioner
San Francisco Redding
WALTER T. SHANNON
Director of Fish and Gome
CALIFORNIA FISH AND GAME
Editorial Staff
CAROL M. FERREL, Editor-in-Chief Sacramento
JOHN E. FITCH, Editor for Marine Resources Terminal Island
ELTON D. BAILEY, Editor for Inland Fisheries Sacramento
MERTON N. ROSEN, Editor for Game Sacramento
DONALD H. FRY, JR., Editor for Salmon and Steelhead Sacramento
TABLE OF CONTENTS
Page
TIk^ Wood Duck in California with Special Reference to the Use
of Xest Boxes A. E. Naylor 241
Use of Desert Slirnhs by Jackrabbits in Northeastern California
Sturfjis McKecvcr and Richard L. Hubbard 271
The A<ie and (Irowth of Striped Bass (Roccus saxatilis) in
California John B. Robinson 27!)
The Ini]iortance of the Ocean Sport Fishery to the Ocean ('atch
'gon and California
Henri/ (). Wmdlrr 2!)1
of Salmon in the States of Washington, Oregon and (California
Tuna Ta-iging' in the Eastei-n Ti-opical Pacific, l!)r)2-ir)5r)
C. E. Blunt. Jr. and James D. Messersinifh :!()1
Note
Toxicity of Ti'icon ()il Spill Eradicatoi- to Striped Bass (Roccns
saxatilis) Harold I\ . Chadn-icl: ■}^^
Note
A Rano'e Extension of the Crdifoi-nia llfdibut (Paralickthys
californicKs) E. G. (inndcrson 873
Reviews 375
( 239 )
THE WOOD DUCK IN CALIFORNIA WITH SPECIAL
REFERENCE TO THE USE OF NEST BOXES'
A. E. NAYLOR
Game Management Branch
California Department of Fish and Gome
INTRODUCTION
Asidi' I'roiii Jiiiiitiim' scnsoii fcsl I'ict ions, llicrc luis been lilllc cn'orl
(lui'iiii;- Ihc I;is1 luilf (-cntui-y hciil lowjird tlii' sliuly and iii<ina<i'('iiu'iit of
tlu' wood duck (^ii.r spoiisa) in ('aliroi'nia. The wood diu-k now holds
a position of secondary inipoi'taiicc witliiii llic Slate. 'I'lus is due to tlie
rathef linnted population and to the haii' limit I'cst i-id ion of one bii'd,
two factors wliicli reduce its utility as a hunting- s[)ecies. In all ])rol)-
ability llie wood duck will always reiuaiu secondary to other species of
watei'fowl in Califonua and will need some tyjie of j)rotection and
assistance to maintain its pi-esent le\-el.
While conii)ilin<i' the early hist()i'\' of the wood duck, it Avas found
that its status varied f>reatiy according- to the obserx-er. -lust how
nnmerons the wood duck was (lurin<>' the early settlenieid of California
is unknown, but it was reported to be conunon and widespread from tlu;
San floaquin \'alley northward.
The wood dnck was fairly abnndaid after iHoO. Kennerly (^1851))
i-ecorded the s])ecies as abnndaid in the \icinity of San Francisco in
Fel)niar\- of isr)4. Fisher (1920) quoted Belding' as reportino' that
when he moved to Mai-ysville in 1S()2 the wood duck was very conunon
along' the Feather River and was a continual resident in that area.
Mailliard (1!»11) reported that it was conunon in Marin and Sonoma
Counties in the ISTO's. Townseud (ISST) stated that the wood duck
was a conunon and comparatively well dist I'ibuted species and it was
observed in cpiite large tlocks along the lower AlcCloud Iviver at \arious
times throughout the fall and winlei-. <ii-innell and Ui-yant (lf»14)
wrote that the wood diick was foi-nierl\- conunon and well distributed
throughout the lowlands west of the Sierra Nevada Mountains.
'file first game law in California was passed in IS.l'J and protected
elk, di'ry, antelope, (piail, mallard and wood duck for six months of
the year. This law ai)plied to only 12 counties, most of which were
submarginal habitat as far as the wood duck was concerned.
The reason for this restriction on the wood dnck was (piite vagne
since at the same time it was considered to be abundant, 'i'his first
game law did little to |)rotei-t the game s])ecies it covered because at the
time there were no game wardens in State employment to enforce
the legislation. Apparently' mai-ket hunting, especially for the valuable
highly colored feathers of the male, bi'onght about this early restriction.
1 Subinittecl for publication March, 1960. A contribution of Federal Aid in Wildlife
Restoration Project W-HO-R, "Watorfnwi Investigation."
(241)
242 CALIFORNIA FISH AND GAME
At tlie turn of tlir century tlie wood duck population was docliuin"'
in numbers. J)ue to tlu' lack of pi'opet' law eid'oi-ceinent, market hunt-
in<:- was continued. Di-ainin^ and reclaimin<i' uuirsldaiuls for ayricul-
tural pni'poses aided in llie decline. Dredtziiej for L;<ild alon<i' the rivers
was another factor in the de<-line. Hoi h land i-eclamation and dred<iin<i'
destroyed the riparian habitat frecjuented by the birds. The wood duck
was reported to be on the verge of extinction by 1914. Griniiell (1915)
reported that the wood duck was then rather rare as a resident in the
Sacramento and San Joaqnin Valleys and westwardly toward the coast.
Destruction of liabitat and overshooting' was the general trend
throughout the nation. The wood duck population became depleted to
such an extent that when Congress passed legislation in 1913 to protect
migratory Avaterfowl, the wood dnck was given complete ])rotection for
five years. More protection was given the species when the Migratory
Bird Treaty between the United States and Great Britain was signed in
1918, devoting Article IV to the special protection of the wood duck
and eider dnck. Complete protection was extended to the wood dnck
until 1942, when one duck was allowed in the hunter's bag limit. Under
this protection the wood duck increased in California as is shown by a
report (Anon. lil^O) which stated "A marked increase of wood ducks
has been noted in California during the past few years. This species
has been protected by law everywhere since the adoption of the Migra-
tory Bird Treaty, and the good results have been apparent in many
parts of the country. One warden rejiorts a concentration of 5,000 wood
ducks congregated on Lake Almanor, Plumas County, and another con-
centration is reported from the Butte Creek section, Butte and Sutter
Counties, where several thousand wood ducks were said to have
wintered."
Stoner (1940) reported that by 1939 wood ducks had increased in
abundance in favorable areas along creeks in Napa and Solano Counties.
The protection given the wood duck from hunting resulted in a gen-
eral increase, but failed to return the species to its original numbers
in most places. More and more land was drained and reclaimed. River
channels were straightened, eliminating the wooded oxbows frecjuented
by the birds. Mature oaks, sycamores and willows, trees most likely to
have nest cavities (Fig. 1) were cut and destroyed. A shortage of
nest sites throughout California was the result. This condition in
California paralleled a similar situation that existed throughout the
nation. It was at this time that the development of artificial nest
boxes occurred. The boxes proved to be successful in wood duck man-
agement and many thousands have been installed throughout the
nation.
OBJECTIVES
The j)rimary objective of this survey was to obtain data regarding
the success of a program of nest box installation. The survey was
meant to be a pilot studj^, with limited scope, aimed toward presenting
recommendations for use in guiding a large scale nest box program,
in the event such a program proved feasible in California. A secondary
objective was the development of an adequate method of determining
the yearly status of the wood duck in California.
THE WOOD DUCK IN CALIFORNIA
243
FIGURE 1. Wood ducks do not nest on the ground, instead they select natural hollows or
cavities in trees.
PROCEDURE
The following is a list of terms and definitions which have come into
common nsag'e dnring the study. This explanation may help to clarify
some of the data in this rejiort.
Site : Each individual unit or area in which nest boxes are located.
A site may contain one or more boxes.
Location : The ti'ee or pole to which the box is attached.
Functional : Any box in a condition to be used by a wood duck or
other animal.
Nonfunctional : Any box which was considered unsuited for wood
duck usage. Some examjilcs of boxes which were considered nonfunc-
tional were those with covers missing, flooded, split badly, or concealed
by vegetative growth.
Wood Duck Usage: AVood duck usage was considered to have oc-
curred if one or more e<iRs were laid in the box.
244
CALIFORNIA FISH AND GAME
FIGURE 2. A shady bank provides a loafing spot for the mole as he waits for the female
during the early stage of incubation. (Phoiograph by F. Dale Horn.)
Percent T^sa^e: The number of boxes used by wood ducks in rela-
tion to tile juuiiber of functional boxes checked.
Double Usage : A box in Avhich one female wood duck hatched off a
clutch with the young leaving the box, and the same box was used
again during the same season by another female as a nest site. These
boxes were recorded as two boxes used by wood ducks in computing
percent of use.
Successful Box : Any box from which one or more wood duck eggs
hatched with ducklings leaving the box.
Percent Successful: The relationship between the number of success-
ful boxes and the total number of boxes used by wood ducks.
Other Usage: All usage other than that by wood ducks is included
in other usage. This included boxes where there was evidence that an
animal had entered the box to den, roost, nest or seek food.
No Usage : If no evidence was found of usage by wood ducks or other
animals, the box was listed as unused.
The procedure used in installation of boxes, exjilained in the follow-
ing paragraj)hs, may save others considerable experimenting in work-
ing out satisfactory methods.
It is impossible to li.st all areas where a wood duck w ill locate. The
way to insure usage is to install the boxes in areas where the ducks
have been known to nest. Nest boxes are needed most where the num-
ber of wood ducks is greater than the number of nest sites available.
THE WOOD DUCK IN CALIFORNIA
245
FIGURE 3. Slow moving streams and small ponds subject to little water fluctuation provide
natural foods and cover for broods. (Phoiograph by F. Dale Horn.)
FIGURE 4. Butte Slough in Sutter County is typical of streams and rivers in the Central
Valley inhabited by wood ducks.
Therefore, the first step in placement of boxes is to determine if wood
dnelvs already inhabit the area in which the boxes are to be placed.
Consnlting- landowners, sportsmen, fish and game personnel working
in the area, or aerial or ground reconnaissance are usually good meth-
246
CALIFORNIA FISH AND GAME
FIGURE 5. Ideal habitat in Shasta County. The addition of nest boxes in areas such as
these increase the production of wood ducks.
ods of discovering if wood ducks occur in a specific area during' the
nesting season.
The best locations for boxes are in open stands of trees along small
streams and ponds. Wood ducks frequent the quiet waters of sloughs,
old river channels, ponds and waterways where oaks, willows and
cottonwoods shade the banks and furnish nest cavities. An impor-
tant need of the wood duck is an area adjacent to the nesting site
which provides resting and feeding cover. In most cases, the birds
prefer the smaller water areas to the larger lakes and rivers. Boxes
should be installed as close to the water areas as possible. Generally,
the greater the distance a wood duck nests from Avater, the greater
the hazard faced by the young in tlieir travel from the nest to the
nearest water. Figures 2-7 illustrate various habitats utilized by the
wood duck.
Since wood ducks do not appear to be particularly adept at locat-
ing nest cavities, the boxes should be placed in areas where they
can be seen easily by the ducks. All vegetation which conceals the
box should be cut away at the time the box is installed.
The height of the box above the ground was not considered too
important as long as it was higher than 10 feet. Boxes placed above
10 feet in trees which were devoid of limbs below the boxes proved
to have less molestation and human interference. Such a situation,
however, required a ladder or climbers and safety belt for the person
checking the box for usage.
THE WOOD DUCK IN CALIFORNIA
247
FIGURE 6. Dredger ponds occur along the western slope of the Sierra foothills but many
lack nest cavities, which makes these ponds ideal for the installation of nest boxes.
FIGURE 7. This small pond in Marin County was considered ideal habitat lacking only
nest cavities. Two pair of wood ducks moved in and nested immediately after the installation
,* ♦,.
:i4c^
CAI.iFOKXIA I'MSII AND (JAM
X I 1/4 Cleats
Top (inside)
T~ '■
4" Shavings
.1
10"
1^
Front
J
II — — .n
25 22
TT
1
^-Drilled hole 7/16"
r
Side
Materials
l"x 12" rough lumber
3/8"x 3 1/2" hanger bolt
3/8" wing nut end washer
2" screen door hooks and eyes
shavings as shown
FIGURE 8. Plan of wood duck nest box. The elliptical entrance usually eliminates pilfering
of the nest by racoons. (Drawn by Cliffa Corson.)
The boxes used were patterned after the U.S. Fish and Wildlife
Service design. Two sizes were nsed during the study. One size was
12 inches square and 24 inches long and the other was 10 inches square
and 22 inches long (Figure 8). There was no definite preference shown
by. the wood ducks for either size of box. By utilizing the smaller
boxes, the cost of materials was reduced.
THE WOOD DUCK IN CALIFORNIA 249
The boxes were coiistrneted of one-inch ron«'h redwood IuihIxm-. The
rough surface of the lumber was an aid to the young in climbing out
of the box. Redwood Avas selected because of its resistance to weather
and rotting, and because it was as cheap or cheaper than rough pine
or fir. However, it was more suscojitible to s])litting.
The cost per unit at the time of construction during this study was
$1.05 for the 22-inch and $1.24 for the 24-inch boxes. This cost in-
cluded the hanger bolt and hardware, but not labor. The cost could
be reduced by buying the material in larger lots.
The box was attached to the tree by a hanger bolt. The box was
hung on the bolt through the hole bored in the back. The wingnut
and washer drew it tightly to the tree. The wingnut could be loosened
to relieve pressure^ as the tree grew. This method of attachment proved
successful and simi)lified installation for the installer. The nesting-
box should be firm and any movement kept to a minimum. A iiail
through the lower tAvo inch(\s of the back of the box was used to steady
it, if needed. Boxes hanging loosely were Tisually rejected by the female.
Potential nest box sites were evaluated with regard to their suit-
ability as wood duck habitat. The factors considered were available
food, nest cover, cover for broods, loafing cover and gencn-al water-
fowl usage. Most of the boxes were installed during the late winter, a
practice which enabled the crew to place the boxes above flood or high
water levels; however, it necessitated evaluating some of the above
factors, such as food and brood cover, at the time of the first box
check in the spring.
A box of sound construction, securely fastened to a tree or pole in
a suitable location, Avere important factors. The joersonnel checking
the boxes, by noting the areas and factors of maximum success, gained
experience of great value for use in the erection of additional boxes.
This experience can eliminate wasted effort resulting from too many
boxes placed in unsuitable sites. Better success Avill result if the men
engaged in the program are familiar with the wood duck's preferences
for nesting sites.
When a box Avas installed, a field data sh(;et Avas filled out recording
general location, installation site, method of installation and rating of
the area as Avood duck habitat. Such data as tree species, height of
box, and direction of hole Avere recorded and proved valuable as an
aid in relocating boxes Avhich were difficult to find. A map of the box
location Avas draAvn at the time and any useful information Avas put
on the map. The maps Avere redraAvn latei- and added to a permanent
file to be used during subsecpient box checks. Each box Avas numbered
to aid in collection of data for the individual nest box history. The
boxes also Avere stenciled Avith information designed to forestall any
human molestation resulting from curiosity or A^andalism (Figure 9).
All boxes Avere checked tAvice during the season. The first inspection
Avas in early May and coincided for the most part Avith the peak of
the nesting season. The nesting season Avas slightly earlier in the south-
ern parts of the range, a condition which allowed the personnel check-
ing the boxes more time to iiisjx'ct all th(> boxes.
'2:)0
CALIFOKNIA FISH AM) (!AMK
l'''^;^"''-*'
'l;'j^
J,3'4^a ii^K'^Ldf.
FIGURE 9. Wood duck nest box showing box number and stencilled information designed
to keep human molestation at a minimum.
The second check was made in July at which time the nesting season
was considered complete. Few, if any, nests were active after July.
The field work was considered complete when the last check was
finished.
During the first check, a nest card, of the Unisort Analysis type,
was made out for each box and pertinent data recorded on the card.
The same card was used also on the second check. A functional box
was checked to determine usage. The boxes which were nonfunctional
were repaired or replaced.
The nests were examined to determine the number of eggs present
and whether they were being incubated. The amount of down present
was recorded, as this usually gave an indication of the stage of in-
cubation.
THE WOOD DUCK IN CALIFORNIA 251
Successful nests were examined to determine the size of the hatch,
the number of eggs remaining and the number of dead ducklings left
in the box. The iiumber of eggs hatched was determined by examina-
tion of the remains and counting the egg membranes which remain
intact even though the shells are crushed.
Unsuccessful nests were examined to determine the reason for their
failure and to ascertain the number of eggs lost, if any. Eggs left in
the boxes were broken to determine if incubation had progressed
enough to be apparent. Desertion was assumed where no eggs hatched
and no definite evidence of interference was observed.
Other usage was recorded by species and the nature of usage. Some
boxes might have been used for nesting or denning, some for roost-
ing, while others might have been visited by an animal in search of
prey.
All boxes with usage data completed were cleaned of egg remains,
down and feathers to prevent confusion in the next year's data. New
Avood shavings were added where needed to maintain a level of about
four inches in the box. Shavings were preferred over sawdust, since
the sawdu.st tended to pack and become hard. A hard packed surface
would not allow the eggs to be buried during the laying period and
might have resulted in the female abandoning the box as a nest site.
WOOD DUCK HABITAT IN CALIFORNIA
Summer Habitat and Population
The greatest population of breeding wood ducks in the United States
is found in the states from the upper Mississijipi River eastward
through New England. Ideal habitat, such as small wooded ponds,
bogs, flooded swamps and slow moving streams, is interspersed through-
out this area.
In California, the summer wood duck population is distributed
sparsely over most of the state north of the Tehachapi Mountains.
Their range includes a tremendous amount of marginal habitat. Much
of this habitat consists of streams, rivers and reservoirs, ranging from
the higher elevations to the river bottomlands in the valleys. Wood
ducks were observed throughout this habitat wherever any effort was
expended on box installation. There were 53 sites in the State where
nest boxes were installed, and wood dncks utilized boxes in 46 of
the sites.
There are, however, some areas of concentrations. These are located
as follows: an area east of Anderson, Shasta County, which includes
many wooded streams and the Sacramento Kiver ; Indian Valley in
Plumas County; along the Feather River in Butte, Sutter and Yuba
counties; the Butte Sink west of Gridley, Butte County; soutli along
the western slope of the Sierras, including stretches of the Cosumnes,
Mokelumne, Tuolumne, Merced, San Joaquin and Kings rivers. Most
of the north coastal streams also are utilized by some breediiig pairs.
These areas mentioned are by no means a complete list of concentra-
tions of breeding wood ducks in California. Other areas undoubtedly
exi.st which were not located during the study.
Most of the available habitat in California is subjected to extreme
fluctuations of water levels. This condition has a detrimental effect on
most wildlife including the wood duck. Unstable water conditions may
2.')"2 CALTFORXIA FISTI AXD r!A:\rE
])lay ail iinportaiit jiai'l in limit ini;- the iiuiiibcr of wood ducks breed-
ing in the State. The niajoi- rainfall in California comes dnrino- the
M-inter months and the How in most streams is ])lentifnl at that time.
liy late spring' the runoff from tlie snow paclv is under way, but much
of this is divertt'il for agricultural |)iiri)oses. The result is a decrease
of water in streams until the flow in early summer is reduced to a
minimum or stopped altogether. This decrease in available water co-
inciiles with the nesting season of the wood duck. The rapid decrease
of water and the lack of natural nest cavities apparently are the
imi)ortant factors in making California habitat marginal. The fact that
California is the southern extremity of the breeding range on the
Pacitic Coast also contributes to the limited breeding populations within
the State.
As a result of field observations during the five-year study, the
annual nesting wood duck population in California was estimated at
1,5UU i)airs.
The estimated breeding range of the Avood duck in California is
shown in Figure 10.
Winter Habitat and Population
California is the major wintering area for the wood duck on the
Pacific Coast. A few stragglers are seen in Nevada and Arizona and
some winter in Sinaloa, in Central Mexico (A.O.U. Checklist, 5th
Edition).
There are more than 25,000 miles of streams and about 6,000 lakes
and impoundments in California and many of those of lower elevation
are utilized by wood ducks during the winter. Wood ducks have been
recorded in the fall and winter from San Diego County, Imperial
Valley, and Death Valley in the south to Humboldt and Siskiyou
counties in the north. They have been reported in Santa Barbara,
Ventura, and Mendocino counties on the coast and east to Yosemite
National Park and Lake Tahoe in the Sierra Nevada Mountains. Cen-
tral California, however, furnishes most of the winter habitat. Oak-
covered foothills bordering the central valleys, the rice belt, and the
river bottomlands are all adjacent to each other and, when combined
Avith the warm winters and abundant I'ainfall, form an ideal winter
habitat.
Although the wood duck is widely dispersed throughout the winter-
ing range, there are areas of concentration. These areas correspond
closely to the summei- concentrations and may be found as follows:
east of Anderson in Shasta County; in the vicinity of the confluence
of Deer Creek and the Sacramento River in Tehama County ; along the
Feather River in Butte, Sutter and Yuba counties; the Butte Sink
west of Gridley, Butte County; in the foothills of the Sierra Nevada
IMountains, including the many rivers and streams draining into the
central valleys as far south as the Kings River ; and on the many reser-
voirs and streams along the Coast and Diablo ranges, south to Mon-
terey County. The wood duck is rarely found along the sea coast or
in the salt marshes.
The winter migration of the resident po])ulation in California
amounts to a shift out of the higher elevations into the central valleys
and adjoining foothills. The central valley is apparently the year-
THE WOOD DUCK IN CALIFORNIA
253
FIGURE 10. Estimated summer (breeding) and winter range of the wood duck in California.
The shaded portions of the map indicate areas of higher densities of wood ducks.
(Drown by Cliffa Corson.)
roiuid range of the wood chieks that breed tliere. The iiiai) in Figure lU
illustrates the estimated winter range in California.
Most of the wood ducks in llie Pacific Fly way are ]> rod need in
Washington, Oregon and California, with linnted i)o|)nlations in west-
ern Montana, northern Idaho and the Cohuubia IJasin in British
Columbia. Recoveries of birds banded by those states indicate a fall
migration into tlie wintering areas of California. The recovery pattern
for banded wood ducks taken in California is shown in Figure 11. As
seen from the map, tlie Coast Ranges north of San Francisco liny, the
Sacramento Valley and the northern San Joaquin Valley are important
wintering areas on the Pacific Coast.
•_':)4
CAMFOKMA I'MSIl AND CA.MK
DEER ISLAND
LAKE TERRELL-
SKAGIT DELTA
Q NINEPIPE N.W.R.
_ SAUVIE ISLAND
j^# SMITH LAKE
• WILLOW LAKE
E E WILSON G. M. A.
ACRESCENT MILLS
•••
At.
FIGURE 11. Migration of banded wood ducks info California. The large symbol indicates the
banding station and the small symbol represents the area of return. (Drawn by C/iffa Conon.)
The extensive habitat in California, coupled with the secretive nature
of the species, makes it very difficult to obtain an accurate census of
the total population. In trying to resolve the question of how many
wood ducks winter in the State, an indirect method was thought to be
best. In this way, by determining the total fall population in those states
where California's wintering wood ducks originate, the California pop-
I
THE WOOD DUCK IN CALIFORNIA
255
Illation conld be calculated. Tabic 1 presents the estimates by water-
fowl technicians of the ])reniijiratioii ])()|)iilations wiHiiii their states
during 1958. It should be kept in mind that the wood duck does not
lend itself to easy census and therefore the figures in the table are
obtained under less than i(h'al conditions and mav be subject to ci'i'or.
TABLE 1
Fall Populations of Wood Ducks in the Pacific Flyway, 1958
Area
Estimated
breeding pairs
Estimated
total fall pojjulation'-
Britisli Columbia. _ .
Washington
200
30,000
100
560
■•7,500
1,500
1,000
37,000
500
Northern Idaho
3,300
35,000
California
7,200
Total
15,860
84,000
1 Arizona and Nevada are not included.
- Where only pairs were given, the total fall |jii|)iilatiiin was computed with averane figures of 70 iieicent
nesting success and four' young |)er hrood fledged.
■' Number of bleeding pairs not given, but an estimated 33 percent were adults.
' .Nesting success at fiG percent, or 5,000 successful pairs, and 4 young per l)niod fli'dged.
As shown in Tal)l(' 1, a])proximately 84,000 wood ducks were present
in the tlyway at the beginning of the 1!)58 hunting season. The esti-
mated number of wood ducks killed in the Pacific l^Tj^way during the
1958-59 waterfowl season was over 22,400 birds (Crissey, 1959). This
estimattMl kill subtracted from the total tlyway population left a post
hunting season population of about 61,600 wood ducks in the flyway.
It was estimated that at least 90 percent of the flyway population, or
about 55,400 wood ducks, wintered in California. The above data are
admittedly rough and unrefiiKMl but they do give a better picture of
the wood duck's status in California as it exists at the present.
There is a definite need for a reliable method of censusing wood
ducks, both in the summer and winter. One of the objectives of this
study was to devise a census method in California, but very little in-
formation was obtained.
Various census methods, including aerial surveys, stream surveys,
and brood counts have been tried by other states, with varying degrees
of success. One of the latest methods, now being tried in other states,
is an evening count at known roosting locations. This method appears
to hold some promise for more efficiency in measuring the trend of wood
duck pojjulations. A report on wood duck research methods (Massa-
chusetts Division of Fisheries and Game, undated) states: "An overall
census of waterfowl populations, however, may be open to wide mis-
interpretation since the degree to which any individual species can be
censused may vary greatly. Wood ducks in jiarticular are difficult to
census at this season. Often the woodies form in bands which frccpient
areas different from those occupied during the summer months. Usually
these areas are swamps, wooded streams, and small areas difficult to
census by ordinary methods. Perhaps the best census of wood ducks
at this season can be obtained by evening flights at known concentration
2r)6
LAl.IFORXTA FTSTT AXO nA^tlE
points. Ill \ic\v of llic uiJiiiy vai'\iii^- influciu'cs which must effect the
eeiisusiiiy- of a wood duck po])ulati()ii it would scciu that more iiiforma-
tiou cau be <>athered from intensive stndy on a few areas than by an
extensive but su|)erficial count on many areas. This is evi(h'nt at h^ast
unlil such lime as cciisiis techiiifines |)rove(l by intensive study cau be
(U'velojx'd and ap|)lied on an extensive basis."
LOCATION OF NEST BOXES
Tlie nest box i)rogTam was started iu California in 1952 on a
very limited scale, with only eleven boxes bein^' erected during the year.
The project was expanded to 47 boxes during 1953 and to 145 boxes in
1954. The number of boxes available fluctuated considerably each year,
due to loss by destruction and to the relocation of some boxes on better
sites. Attention was given lu-imarily to a waterway or an area consid-
ered to be good habitat. The region and county in which it was located
was of little significance. The number of boxes in the various counties
is shown in Table 2.
TABLE 2
Location and Number of Wood Duck Nest Boxes Installed 1952-1956
Region
County
Number
Region
County
Number
Region
County
Number
I
Shasta
Humboldt- -
Modoc
Lassen
Tehama
Total
13
12
4
3
3
II
Plumas
Yuba
Colusa
Sacramento
Sutter
Yolo
Butte
Total
19
16
11
6
5
5
4
III
IV
Lake
Marin
Mendocino
Total
Merced
Fresno
Total
6
5
2
13
23
15
3.5
66
38
All Hcsions sniiul total 152
As illustrated in Figure 12, most of the major river drainages were
sampled. For the most part, wood duck habitat in California is associ-
ated with the streams and rivers. Small permanent ponds and bogs do
not exist in any number. AVhere small ]ionds and water areas did exist,
an effort was made to erect boxes on those sites, ^lore work should have
been done on the many dredger ponds along the western slope of the
Sierra Nevada Mountains. The number of boxes installed and the areas
covered were consider(Hl sufficient to ]~iermit an evaluation of the
program.
NEST BOX UTILIZATION
Wood Duck Usage
Percent of Boxes Used
It may be determined from Table 3 that an average of 42 percent of
the boxes were used by wood ducks. Usage of the boxes by other
wildlife w^as recorded in 31 percent of the functional boxes. There w^as
no activitj' recorded in 31 percent of the boxes.
THE WOOD DUCK IN CALIFORNIA
257
•■^^o-c-^Q
FIGURE 12. Wood duck nest box sites in California. Each dot indicates one or more nest
boxes installed in the area. (Drawn by Clifia Corson.)
The degree of usage by wood ducks varied greatly througliout the
different areas in the State. The boxes filled a vital need in areas where
natural cavities were lacking, while in other arenas of equal appearance
oidy limited use occurred. In areas of limited tiest box use, it was
assumed that the number of natural cavities was sut^cient, that there
was a small population of wood ducks present, or that some other fac-
tors influenced th(> nesting. Figure 18 illustrates typical wood duck
usage.
Nesting Period
The beginning of the nesting season in California depended upon the
particular area under consideration. The nesting cycle usually began
earlier in the southern part of the range and was progressively later
27)8
CALIFORNIA FISH AND GAME
O
"3
o
H
c
Oh
M O — ' -H
--. 00
8
M ^ ^
-r CO M
-t"
o
0)
05 00 M 00
(N >0 00
00
-f o> N
CO ^ CO
.— ( T-H »-H
o
to
13
£
Oh
1 O 02 ^
1 ^H i-H t>.
o
o
t^ t- IM
lO (N C^l
§
(1)
c
1 -1- 10 lO
1 -H C>) 02
-f CO' -H
to CO (N
o
c
It
p
O Li O 05
-H 1^
lO rt 00
-f CO CO
o
t-H
S
03 t^ -f ,-^
-r
O -f —
lO CO CO
LO
•o
02
a
0)
o
0)
Oh
1 LO 00 t^
1 00
^H
O 03 -f
CO 0.) -ft
2
0)
s
2
1 t^ (M to
1 rt (M
00 t^ >o
CO CO »o
o
CO
I— 1
c
1 1 IM 00
1 1 Oi
o
o
03 02 0
CO CO O)
o
1
1 1 T)>
00 00 c^i
00
02
G
Oh
1 . Oi —
1 1 CT,
o
o
o o o
-r -f CO
o
u
Xi
s
1
1 1 ^ O
-
-t* -r CO
-
; 1 "3 '
( -o C „
1 « O i.
.S -g 3 ■;3
•? o o S
c c c ^
S S S S
X X X X
o o o o
05 03 OP 05
-o
—
c
0)
X
o
3
o
H
-1^ ai 1
^=5 ;
3 ^ 1
-a t. 1
O 1^
* O '
S2 SS S
CO CO CO
O OJ OJ
XXX
O 0 o
fO 05 05
3
0
hn
(IJ
O'
o
o
o
£ 2.
o
t3
M
•a
CS
<^
S3
■^ o
THE WOOD DUCK IN CALIFORNIA
259
FIGURE 13. A nest box used by a wood duck. Note the abundance of down which is
typical of wood duck nests.
.'(iO
CALIFORNIA FISTT AXO GAME
o
GO
1
o
H
4^
p
s
Pi
CC 00 o tc
o
o
lO M CD O
(M —1 >-i rt
"f
I— (
-(J
g
iM CD' CO 0-.
o
o
03 CO t~ »o
CO
I— (
a
o
PM
^^00-.
§
1
O) !M -t (M
1<
o
in
Oh
c-i CO o o
00 -H
o
o
1
^ lO O) o
CO
00
CO
C
P-,
■-I r^ ,-( ^
O rH rt ^
§
T-H CO IM <N
00
I—t
03
1— 1
a*
O O lO lO
o
o
1—*
(M O •-I --1
•1<
<p g to 1
C3 C g »
2 S S 3
fZQQO
r/i
0)
CI
o
H
THE WOOD DUCK IN CALIFORNIA 261
to the north. Average dates taken from known nesting- pcM'iods in wood
dnek boxes indicated egg laying started about the last Aveek of Alareli
ill tlie Sail -loaquin Valley and during the second week of April in
Pliuuas and Ihnnboldt counties. In general, the nesting season was usu-
ally in progress throughont the State after the middle of April. Nesting
activity progressed at a more liesurely pace in the soutlun-n portion of
the range. Most of the nesting activity was eom])lete(l by -Inly 15 ex-
cept for an occasional late nest or a reuesting attempt.
Nesting Success
A nest was considered successful if one or more ducklings were
known to have departed from the box. Only in one instance did all
young fail to leave the box after hatching. In every successful nest,
the characteristic egg membranes and caps were found in llie box. The
presence of these remains was Ihe criteria used in deteriniiiinu llie
fate of the nest.
During the five-year period, ii(>st history data were recorded on
164 wood duck nests. Of these, 125 nests (76 percent) were successfully
hatched, 16 (10 percent) were deserted, 13 (8 percent) were destroyed
and 10 (6 percent) were recorded as dump nests. Table 4 summarizes
all data gathered of the fate of nests throughout the study.
Cluich Size
Clutch sizes ranged from a iiesi containing one egg to ;i diiiiip nest of
43 eggs. Successful clutch sizes ranged from 3 eggs to 28 eggs and tlie
average, based on 125 successful nests, was 13.3 eggs per nest (Figure
14). However, this average clutch size was considered to be biased by
the influenee of parasitism of nests by other females. Nests containing
10 to 14 eggs made up 52 percent of tlie successful nests and represented
those nests in which a minimum of parasitism had occurred. The aver-
age clutch size of tliis group of nests was 11.8 eggs and was considered
to be a more valid figure for wood ducks.
A dump nest was defined as the product of more than one female
and no attempt was made to incubate the eggs. A total of 10 dump
nests were recorded during tlie study which contained 285 eggs. The
average clutch size for dump nests was 28.5 eggs per nest. The dump
nests and large clutch sizes of successful nests indicated that there was
c()nsidera])]e competition among the females foi- nesting sites. Addi-
tional boxes installed in the areas of competition would have helped
to alleviate this condition.
Hatching Success and Production
Successful nests contained a total of 1,663 eggs, of which 1,2!)5 or
78 percent hatched. The young experienced little difficulty in leaving
the boxes after hatching. A total of 1,253 (97 percent) ducklings
scrambled out of the boxes during the study. Data obtained on nest
box utilization by wood ducks is summarized in Table 5.
Unsuccessful Nests
Unsuccessful nests Avere recorded ;is deserted or destroyed. Dump
nests were included in this category for lack of a better place. A total
of 39 nests (24 percent) were classified as unsuccessful during the
study.
2G2
CAI.IFOHXIA FISH AND GAISIE
±^^
■r-r-T
{■ . I- :j:
lO^
in
CM
O
(T>
00
(D
in
K5
00
Oi
00
in
a ro
CO
10 in 't ro c\J
OCDODN-tDin'+rOCO —
^
u
CM
0
u
rO
0
CM
tt
U
CM
CO
ja
X
o
J3
m
C/)
c
o
3
-n
(JD
III
T!
U.
T3
O
0
u
cc
V
UJ
t/i
CD
ID
- =) -^
■D
c
D
0)
E
3
Z
UJ
Of
=)
o
SiS3N JO aaaiNnN
THE WOOD DU(!K IN CALIFORNIA
203
TABLE 5
Summary of Wood Duck Nest Box Data
Total wood duck nests
Total eggs, all nests
Average clutch, all nests
Successful nests
Total eggs, successful nests
Average clutch, successfvil nests _
Total eggs hatched „ .
Average hatch in successful nests
Total young produced
Total young leaving boxes
Average young leaving eacli box.
Percent of young leaving boxes. _
1952
4
61
1.5.3
2
24
12.0
24
12
24
24
12
100
1953
18
265
14.7
11
154
14.0
122
11.1
122
118
10.7
97
19.54
38
483
12.7
31
438
14.1
344
11.1
344
.335
10.8
97
19.55
50
644
12.9
42
516
12.3
438
10.0
438
422
10.0
96
19.56
54
764
14.1
39
.531
13.6
367
9.0
367
3.54
9.0
96
Total
164
2,217
13.5
125
1,663
13,3
1,295
10.4
1,295
1,2.53
10.0
97
Desertion was recorded in 16 (10 percent) nests. Desertion was
assnined where no definite evidence of interference was observed. The
causes of desertion are very difficnlt to determine. Competition among
females for nesting sites, hnman interference and competition with
other species of wildlife for nse of boxes were considered to be causes
of desertion.
There were 13 nests (8 percent) destroyed. The main factor causing
nest destruction was attributed to human molestation. Human moles-
Uition accounted for a total of eight nests that were broken up by the
removal of eggs or destruction of boxes containing nests. Raccoon
j)redation, which is prevalent in nest box ])rograms in eastern states,
was found in onl}^ two boxes and suspected in two more during this
study.
8ix ])ercent (10 nests) of the boxes used by wood ducks contained
dump nests.
Other Usage
In addition to usage by w'ood ducks, the boxes provide nesting and
resting sites for many other species of wildlife. The other species were
considered a nuisance as far as the wood duck nest box program
was concerned. A total of 119 boxes (31 percent) was occupied by 12
species other than wood ducks. Those most commonly found using the
boxes were sparrow hawks, honey bees and screech owls. Table (i pre-
sents a list of wildlife, other than wood ducks, utilizing the boxes dur-
ing the study.
Nonfunctional Boxes
A box was considered nonfunctional w^hen there was a condition
present to impede usage. Such conditions included tops missing from
boxes, absence of shavings in box, large splits in box sides, box con-
cealed by vegetation, boxes which had fallen down, boxes flooded by
high water, and some types of human molestation such as shooting
boxes.
A total of 450 boxes was checked during the study and 51 (11 per-
cent) were found to be nonfunctional. As the boxes became older the
l'(i4
rATJFORXTA FTSn AXD G.\:\rK
TABLE 6
Number of Boxes Used by Other Wildlife
olJccies
Number of boxes
Percent
27
22
23
19
21
18
11
9
8
7
8
7
6
5
5
4
4
3
3
3
2
2
1
1
119
100
Sparrow lunvk
Honey bees
Screech owl
Red-sliaftod flicker..
Kinstuiled cat
Tree swallow
Brown rat
Barn owl
Bird (unknown)
Wren
English sparrow
Mammal (unknown)
TotaL
number that Avere iioiifvinctional increased proportionately (Figure
15). As a resnlt of flood conditions throngliout California during the
winter of 1955-56, the number of nonfunctional boxes nearly doubled.
Many of the trees containing nest boxes were knocked down by the
flooding streams and rivers.
MAINTENANCE
Tlie number of boxes successfully used by wood ducks each year
ultimately determines the value of the program. Sucli a program can-
not rest with the initial installation of the boxes but must have mainte-
nance that is both adequate and continuing. In a successful program,
boxes must be in a condition acceptable to the birds at the beginning
of each nesting season.
It was found that soundly constructed boxes of good lumber resisted
deterioration for long periods. However, when wooden boxes are used,
maintenance and upkeep become a part of the program. Boxes that
were destroyed by flooding, vandalism and irreparable splitting had
to be replaced. The replacement of destroyed boxes Avas carried out
at the time of the nesting checks during the summer. Nonfunctional
boxes Avere repaired AA'hen found. The major cause of nonfunctional
boxes Avas the occurrence of large splits in the sides beloAv the entrance
hole. In most cases, such boxes were not accepted by female Avood
ducks as nesting sites. Black weather stripping cement Avas squeezed
into the split, which Avas then closed AAdth a feA\^ corrugated fasteners.
This method proved to be successful and little time AA'as required to
repair a box in this manner.
Extra lids AA'ere carried at all times and AA'ere used as replacements
AA'here needed. Shavings Avere often removed from a box by other Avild-
life and it became standard procedure to have extra shavings along
AA^ien checking the boxes for usage. In some areas, especially the north
coast, the boxes were concealed by rapid vegetative groAvth after their
installation. This ncAV cover needed chopping away each year (Fig-
ure 16)..
THE WOOD DUCK IN CALIFORNIA
265
25
20 -
< 15
o
o
3
Ll
»
O
10
UJ
o
UJ
^///y
^
1
il
iP
fy^-
M
m
P
M
il
p
i
M
^
^
i
12 3 4
NUMBER OF YEARS INSTALLED
FIGURE 15. The percentage of nonfunctional boxes in relationship to the length of time
that the boxes were installed. (Drawn by Cliffa Corson.)
During the early part of the study, considerable trouble was caused
by honey bees. They took over nest boxes and used them as hives.
Tlie boxes containinji' bee hives were poisoned with cyanide during- the
winter when the colony of bees was dormant. The boxes were then
266
CALIFORNIA FISH AND GAME
FIGURE 16. This box in Humboldt County was concealed by vegetative growth and was
considered nonfunctional.
cleaned out and replaced. Some experimenting was done witli repellents
and the following thi'ee types were used with success:
1. Four ounces of chlordane added to one gallon of black creosote.
2. One ounce of chlordane to one (|uart of motor oil.
3. Fifty percent wettablc DDT nuxed to a paste with water.
The honey bees attached their comb to the lid of the box, as shown
in Figure 17, so only the lid of a box was treated with repellents. The
lids of all boxes were treated during the first check of each year after
1953. Honey bee usage was reduced to a minimum after the repellents
were used. During the 1953 nesting season 35 percent of the boxes were
occupied by honey bees. After a winter application of rej^'Ucuts less
than two percent of the boxes contained bees in the 1954 nesting
season.
Female wood ducks showed no aversion to occupying a treated box ;
nest abandonment due to the repellents never occurred.
The use of repellents will be a necessity in nest box programs in the
Sacramento and San Joacpiin VaHeys where the majority of the bee
usage occurred.
Some states now have gone into })rograms using metal boxes. These
boxes are cylindrical in shape and are constructed of galvanized, sheet
metal, cold air pipe. They were designed to reduce nest predation and
to increase the durability. Although metal boxes were not used in tit is
study, they should be considered in any future programs.
THE WOOD DUCK IN CALIPOKXIA
267
:«*
FIGURE 17. The lid of a nest box with attached honey comb. The lids were treated with
repellent to minimize this usage.
268 CALIFORNIA FISH AND GAME
CONCLUSIONS
It was coiicludcd that nest boxes eould have a d(^finite beariii<i' on
llir number of wood dneks prodneed in California each year. A
eoortlinated prourani conld lie int(><irated into tbe unit manao-ement
system used by tlie I'alit'ornia Depai-tment of Fisli and Game with
littk^ eonfliet of j)resent duties. Unit managers eould guide the et¥orts
of boy seout groui)s and sportsmen clubs interested in enhancing
tlie liabitat of Avood ducks. The installation of boxes eould be aeeom-
jdislied during slack work periods and the checking of success carried
in a short period during the spring.
If a sufficient iinmber of boxes could be installed, breeding popula-
tion trends could be correlated with the Avood duck usage in the
nest boxes.
SUMMARY
1. Information is ju-esented on the early history and abundance of
the wood duck in California. Destruction of habitat and overshooting
caused the early decline in numbers of wood ducks. Hunting restric-
tions have resulted in a partial recovery of the sj^ecies.
2. The summer range extends over much of California north of the
Tehachapi Mountains. The breeding po]iulation was estimated at 1,500
pairs. California is the major wintering area for wood ducks on the
Pacific Coast. Central California furnishes habitat for most of the
estimated wintering pojnilation of about 55,400 wood ducks.
3. A five year study, 1952-56, was conducted to determine the feasi-
bility of a nest box program.
A total of 152 boxes was installed and 42 percent were used an-
nually by wood ducks.
Seventy-six percent of the nests hatched successfully. The average
clutch size of successful nests was 13.3 eggs. Dump nests averaged
28.5 eggs per nest.
Desertion was recorded in 16 percent of the nests; destruction oc-
curred in eight percent of the nests.
4. A total of 119 boxes (31 percent) was occupied by species other
than wood ducks. Sparrow hawks, honey bees and screech owls were
most commonly found using the boxes.
5. An average of 11 percent of the boxes was found to be non-
functional each year.
6. Adequate maintenance must be included in any program of
nesting box installation.
ACKNOWLEDGMENTS
The success of the nest box study was due largely to the efforts
of many employees of all branches of the California Department of
Fish and Game. All personnel of Federal Aid in Wildlife Kestoration,
Project W30R, assisted throughout the study. Richard Robinson of
Fresno State College located many of the nest box sites and re-
corded information on the wood duck in the San Joaquin Valley.
Humboldt State College students assisted with construction and in-
stallation of the boxes in Humboldt County. Appreciation is due to
the members of the Pacific Flyway Technical Committee and especially
Chester Kebbe of Oregon, Robert Salter of Idaho, Robert Jeffery of
THE WOOD DUCK IN CALIFORNIA 269
Washington, Ron Mackay of British Colnmbia, and Dwight Stoek-
stad of Montana, who compiled popnhition data for their respective
states. Special thanks are given lo the landowners thi-ongliont the State
who pci'Hiit ted iiuresti'ictcd ficccss lo tlicir land dnring the stndy.
LITERATURE CITED
American Ornithologists Union
1957. Clieck-list of Nortli Anu'i-icini liinls. Kiltli cd., Tlic Lord T.iilt iinor." T'n'ss
Inc., Baltimore, 691 pp.
Anonymous
1030. Wood Ducks — ITow i,> disliuKuisIi llinii. Talif. Fisli .-ind flanie, vol. If.,
no. 4, p. 342.
Crissey, W. F.
1959. 1959 Status report of waterfowl, Wildlife No. 45. U. S. Fish and Wildl.
Serv., Spec. Kci. Rpt., Wash. 25, D. C, Multilith 1(t9 i.p.
Fisher. A. K.
1920. In jMeiiKii'iain : Lyman lieldinj;-, .\\\k, \iil. 37, no. 1. i)p. 33-45.
Grinnell, .Toseiih
1915. A distril)utional list of tlie birds of ( 'aliforiiia. I'.-icilic Coast Avifauna,
no. 11, 217 pp.
Grinnell, Joseph and Harold C. Bryant
1915. Calif. Fish and Game, vnl.'l, no. 2, pj). 49-.52.
Kennedy, C. B. II.
1859. Report on birds collected on the route. Pacific Railroad Reports, vol. 10,
pt. 6, no. 3, War Department, Wasli., !>. C., pp. 11-35.
Mailliard, Joseph
1911. Odds and ends. Condor, vol. 13, no. 2, p. 49.
Massachnsetts Division of Fisheries and (lame
Undated. Sununary of wood duck research methods. Mimeo., 14 pp.
Stoner, Emerson A.
1940. AVood ducks in Solano and Napa Counties, California. Condor, vol. 42,
no. 3, p. 170.
Townsend, Charles H.
1887. Field notes on the mamnntls, birds and reptiles of iiorllier-n r.-ilifornia.
Rroc. U.S.N.M., vol. 10, pp. 159-241.
2—17250
USE OF DESERT SHRUBS BY JACKRABBITS
IN NORTHEASTERN CALIFORNIA'
STURGIS McKEEVER
Department of Zoology, University of California, Davis
and
RICHARD L. HUBBARD
Pacific Southwest Forest and Range Experiment Station
U.S. Forest Service, Berkeley
INTRODUCTION
Obsorvations by tbe antbors wbih^ doing field Avork indicated tbat tbe
jaekrabbit (Lepus calif ornkus) approaebed or reaebed a peak in popu-
lation density in 1958-59 in northeastern California. Tbese observa-
tions were substantiated by tbe number of requests received by the
Lassen County Agricultural Commissioner for poison for jackrabbits.
Requests reached a maximum number in 1958-59 and decreased in
1959-60. Furthermore, those ranchers who requested poison in 1959-60,
reported that jackrabbits were much less abundant than they were
the previous year.
Particularly heavy concentrations of rabbits were noted on certain
areas, and desert shrubs on these areas were used intensively for food
by the rabbits. To determine the degree and type of use being made
of the various si)ecies of shrubs, a study was made at Turtle Point,
near Herlong, Lassen County, California. The area lies at the western
edge of the Great Basin and immediately east of the Sierra Nevada
escarpment.
STUDY METHODS AND DESCRIPTION OF VEGETATION
A transect of sixteen 1/20-acre plots was located at right angles to
an east facing slope, extending from an elevation of 4,120 feet down
to 4,065 feet (Figure 1). A random starting point was chosen and
l)l()ts were taken at tAvo-chain int(>rvals along a predetermined bearing.
Jackrabbit use consisted of browsing and girdling. Browsing was
tabulated as light (trace browsing), moderate (up to 14 of main
branches browsed), and heavy (14 or more of main branches browsed).
Girdling was tabulated as tiie percentage, to the nearest 10 percent,
of main live stems showing some degree of girdling. The degree of both
types of use for a given plant was based upon a subjective estimate by
the senior author.
Vegetation on the area was composed principally of eight species of
shrubs. At the highest elevation, desert peach (Frunus under sonii) was
the predominant species, with some big sagebrush (ArUmisia triden-
tata) and bitterbrush (PursMa tridentata) present. As the elevation
1 Submitted for publication January, lOfiO.
(271)
272 CALIFOKXIA FISn AND GAME
FIGURE 1. View of area where study was made. That portion of the area immediately
beyond the shrub type was covered with a pure stand of winterfat. August, 1959.
decreased, composition of the vegetation changed ; at the lowest eleva-
tion was a pure stand of four-winged saltbush (Afriplex cancscens)
(Table 1). Beyond the saltbush, but not included in the transect, was
a pure stand of wdnterfat (Eurotia lanata).
RESULTS AND DISCUSSION
Girdling was confined principally to hopsage (Grayia spiiiusa),
desert peach, and horsebrush (Tetradymia glahrata) (Figure 2). Hop-
sage showed heaviest use with 79 percent of the plants showing some
girdling, and all the main stems girdled on 51 percent of the jilants
(Figure 3). Desert peach showed some girdling on 72 percent of the
plants, and 17 percent had some use on all the main stems.
All of the large main stems on many plants had been killed by
girdling, and new sprouts had developed from the roots. Only 16 per-
cent of the horsebrush had any girdling.
Minor girdling was found on three other species. One bitterbrush
plant showed less than 10 percent use, two rabbitbrush plants (Chry-
soiliamnus luiKseosns) showed 10 and 20 percent use, and one four-
winged saltbush showed 50 percent use.
All of the eight principal species of shrubs showed some browsing
(Figure 4). Four-winged saltbush and hopsage had some browsing on
all plants, with 79 and 70 percent, respectively, in the heavily browsed
USE OP SHRUBS BY JACKRABBITS
273
tt>
5 E
m
o ,—
:= rsj
<-> J2
. o
o .«
CO
•d
o
°- §
t— CO
ra
tl o.
<u "*~
O
CL
E
o
otal
by
lots
oo^Oi>-Hioi-ic<5oo^io>raoiiooi-to
Ol
•t^^ior^ioooiooiOsasOOOiO'^iN
•1<
H a
.— t rH
I-H
i-T
o e
OOOOOOOOOOOOOO'^O
»-H
b s
^ a
6q -2
e
^
iMOOOi-iOOOOOOOOOOO
00
0.
-^
« a
•a s
00000000^'-*OOC000050
IM
(-( (N <N
t^
03
to =S
i s k
hrys
amn
idifl
.-H C-l O C-l O -H -r -- — 1 00 O M -*< lO 00 o
(N
t— 1 ^H fH -Tt^ 1— 1
CO
^« g
*r-
?5
00
ryso-
mnus
seosu
m
§ ^(^TliTticD^OOO'-i'tiOOCOwO
CJ
^ T-t tM IM C'S
-« e s
P. "
t-H
O -s 8
^
'^ s
o
01 -
J
3
e 8
s
:3
|7
^^
^-s
i-H CO ^ '-' CO CO <-!
o
C-1
^ -s
-^ ^
■iSi
Co S
s s
s «
(MC0'^00'-<-l<C0O3O1<01!MOOOO
CO
g »
(^^
^ r-t i-H CO
T— (
c-t
a
OlOOlMCOOOOOOOOOOOO
CO
s -e
a^X
■§ i
= 1
000<NCOOi-iO>i>Jt^'-iOC>1000
lO
^1
e
•r^
S|
OX^OOt^OiOCDOSt^iOOO-^COOO
00
r-lMCO INi-HC0in>-llMINCO
CO
•G "■*
^ C»
E^
t
m
t-H
03
(~l
■*^
o|
o
Si
« ,-(^if0M<'0tDt~00OlO'-HIMe0-t"'O'i
13
a
03
274
CALIFUKXIA FISH AM) (lA.Mt:
TtTRADTMIA GLABRATA
I
BB^
I""? f? f? f^ '^ f? I o"o"o' Q
GRAY I A SPINOSA
i
^frwTZT'Wi
PRUNUS ANDERSONII
Jii
WHwwwwC?^'
PERCENTAGE OF MAIN STEMS GIRDLED
FIGURE 2. Degree of girdling of desert shrubs by jackrabbits near Herlong, Lassen County,
California.
class (Figures 5 and 6). Seventy-six percent of the bitterbrush were
browsed, but none fell in the heavily browsed class. Desert peach
showed some use on 72 percent of the plants, with 30 percent heavily
browsed. Sixty percent of the big sagebrush were browsed, and 26 per-
cent showed heavy use.
Only minor browsing was found on the other three principal species.
Thirty percent of the horsebrush plants showed use, but only 2 per-
cent were in the heavy class. Chrysofhamnus nauseosus showed some
browsing on 34 percent of the plants, with 12 percent in the heavy
class. Twelve percent of the C. viscidifloriis plants had been used and
three percent were in the heavy use class.
No tabulation was made of browsing of winterfat, but it was esti-
mated that over 90 percent of the plants near the shrub type showed
some use. In this type, as in the shrub type, rabbit pellets were very
abundant (Figure 7). Use of winterfat diminished as the distance
from the shrub type increased, probably because winterfat does not
provide adequate cover.
It is conceivable that the composition of the desert shrub type could
be altered by jackrabbit use of the intensity described here. Browsing
and girdling of hopsage and repeated girdling of desert peach could
result in partial elimination of these two species. Heavy browsing of
USE OF SHRUBS BY JACKRABBITS
275
FIGURE 3. Girdling of hopsage by jackrabblts. July, 1959.
■i
DtGREE OF BROWSING
I I NOME
LIGHT
MODERATE
HEAVV
n
¥
%
1
I
TETRAD VMI« I GRATIA I PURSHIA 1 P RUNUS I ARTIMISIA I CHRYSOTHAMNUS I CHRTSOTHAMNUS I ATRIPLEX 1
CLABRATA SPIROSA TRIDENTATA ANDERSONII TRIDENTATA NAUSEOSUS VISCIDIFLORUS CANESCENS
FIGURE. 4. Degree of browsing of desert shrubs by jackrobbits near Herlong, Lassen County,
California.
276
CALIFORNIA FISH AND GAME
FIGURE 5. Four-winged saltbush showing extremely heavy browsing by jackrobbits. July, 1959.
FIGURE 6. Hopsoge which has been heavily browsed by jackrobbits. July, 1959.
USE OP SHRUBS BY JACKRABBITS
277
FIGURE 7. Winterfat which has been heavily browsed by jackrabbits Notu ihe clipped but
uneaten items on the ground and the heavy concentration of rabbit pellets. August, 1959.
four-winged saltbusli conld result in suppression of this species. The
other species probabl^y would be little affected once established, but a
high population of jackrabbits could prevent survival of seedlings.
SUMMARY
High densities of jackrabbits were observed in northeastern Cali-
fornia in 1958-59, and on some areas desert shrubs were used inten-
sively for food by the rabbits. A study was made to determine the
degree and type of use.
Girdling occurred principally on hopsage, desert peach, and horse-
brush; the degree of use was 79, 72, and 16 percent, i-espectivoly. All
main stems were girdled on 51 jiercent of the hopsage plants.
All of the principal shrub species exhibited some browsing. Four-
winged saltbush and hopsage were the species most used ; all plants
were browsed to some degree, and 79 and 70 percent, T'esi)ectively, Avere
heavily used. Seventy-six percent of the bitterbrush, 72 percent of the
desert peach and 60 percent of the big sagebrush were browsed, but
heavy browsing occurred on no bitterbrush, on .'30 percent of desert
peach, and on 26 percent of big sagebrush. Less tban .SO percent of the
horsebrush and rabbitbrush were browsed.
Use of desert shrubs for food by jackrabbits, at the rate observed
during this study, could result in a change in composition of the type.
Hopsage, desert peach and four-winged saltbush would be the species
most likely to be eliminated or suppressed.
THE AGE AND GROWTH OF STRIPED BASS
(Roccus Saxotilis) IN CALIFORNIA'
JOHN B. ROBINSON
Inland Fisheries Branch
California Department of Fish and Game
INTRODUCTION
By far tlie most important population of striped bass in California
is centered in the San Francisco Bay area and the lower reaches of the
Sacramento-San Joaqnin river system.
Over the years, angling- pressure on this population has increased
markedly, and many changes have occurred in the environment of this
|)opular game fish. An understanding of the effects of these factors on
the population is highly desirable for management purposes. A thorough
knowledge of the life history of the fish is essential in achieving such
understanding, and age and growth characteristics form an important
phase of life history.
The only previous extensive growth study of this popidation was
made by Scofield (Ifl.'U). Length-weight-age relationships were de-
termined by Clark (1938), using Scofield 's age material. The present
angling regulation fixing the niininimn lengtli limit at IG inches is
based on this early work.
Since the changes in fishing ])ressui'(' and Ihc eiiviroiunenl tlial have
occurred during the intervening years conld have affected the growth
rate, and in the light of the previously stated considerations, another
age and growth study was initiated during the fall of 1957.
METHODS AND MATERIALS
A total of 1,089 scale samples was collected from striped bass caught
by angling in San Pablo Bay and the lower SacranuMito-San .Toa(|nin
Delta area during the fall of 1957 and summer and fall of li)58. Sevei-al
scales were taken from the left side of each fish in the area above the
lateral line and below the origin of the second dorsal fin. Key scales
were not used. Fork length, weight, and sex were recoi-ded for each
fish. The sex was determined by examination of the gonads.
In the laboratory, three scales that were not torn or regenerated
were selected from each sample. These were cleaned and impressed on
1 X 8 X 0.080-inch cellulose acetate slides. Scales from 188 fish were
unusable, leaving 951 for the study.
An Eberbach scale projector with a 32mm. IMaci-o Tessar lens pro-
viding a magnification of 42x was used to age and measure the scales.
They were aged by counting annuli, which Scofield had shown to be
valid. The locations of the focus, the annuli, and the scale margin for
1 Submitted for pul)lication February, lOfiO. This work was performed as part of
Dingell-.Iohnson Project California' F-9-R, "A Study of Sturgeon and Striped Bass,"
Supported by Federal Aid to Fish Restoration funds.
( 279 )
280
CALIFORNIA FISH AND GAME
each scale - Avere marked on a paper strip for later use in determining
the body lenp'th-scale length rclationsliip and in back ealenlating
growth. All scales were aged independently by two men, and the
few scales on w'hicli they could not agree were rejected for growth
calculations.
The radius of each scale Avas measured to the nearest millimeter,
and averaged for the three scales from each fish. The fish were then
grouped by scale radius intervals of one centimeter and the mean body
length for each group was found using the method of Whitney and
Carlander (1956). The body length-scale length relationship was then
determined by plotting the mean fork length of the fish in each scale
measurement group against the scale length and fitting a regression line
to the data.
The back calculation of growth was accomplished using a direct
proportion nomograph corrected for the Y axis intercept.
•The length-weight relationship was determined by grouping the fish
by one-inch body length intervals and computing the mean fork length
and weight of the fish in each interval. These averages were then con-
verted into logarithms and the linear regression was used following
the method described by Sigier (1953).
- All scale measurements were made along the radius from the focus to the center
anterior edge.
JD
Y= 0.97-1- 0 77 X
t
30
N =951
j/^ •
/ 1
,n 25
V'
LlJ
X
o
z
• >^
?20
•j^
■
1
X
en
FORK LENGTH OF
y
X
y
/
y<
5
./
y-
•
5 10 15 20 25 30 35
ENLARGED SCALE RADIUS MEASUREMENT IN CENTIMETERS
40
50
FIGURE 1. Striped bass body length-scale length relationship.
AGE AND GROWTH OF STRIPED BASS
281
RESULTS
Body Length-Scale Length Relationship
The relationship between body length and scale length is shown in
Fig-nre 1. A straight line fitted to the points by the least squares
method is described by the formula Y = 0.97 + 0.77X, where Y is the
fork length of a fish in inches, X is the enlarged scale radius measure-
ment in centimeters, and 0.97 is the Y axis intercept of the regi-ession
line in inches. Since the smallest fish sampled were three inches long,
tlie Y intercept is an artificial value significant only for back calcu-
lating growth and is not necessarilj^ the body length at time of scale
formation. The linear relationship between scale length and body length
indicates that scale length and body length of striped bass increase
proportionately at least from H inches to 34 inches. Scofield (1931)
and ^lerriman (1941) also found a proportional relationship within the
size ranges they studied.
Growth
The growth histories of all fish of ages II through IX were calcu-
lated. Age I fish were not used because of the difficulty encountered
in determining sex. The mean length at the end of each year of life
was calculated separateh^ for each fish, and these lengths were aver-
UJ
I
O
z
UI
UJ
(T
O
z
I
»-
?
o
cr
C5
FIGURE 2. Growth of striped bass as calculated from scales. Upper lines (A) show rate of
growth. Lower lines (B) indicate annual growth increment.
282
CALIFORNIA FISH AND GAME
average annual increments of growth were then de-
aged to get a iiu-aii Icngtli at the end of each year of life for each age
jjronp for each sex '/lables 1 and 2). The means for each year of life
wer« then averaged by sexes to get the weighted ^rand averau'e calcu-
lated length. The
termined for each year of life (Tables 1 and 2).
These data indicate that male and female striped bass grow at the
same rate for the first three years of life. >Subsequently, females grow
faster. The greatest difference in annual growth was reached at ages
VII and VIII, when it was 3.0 inches and 3.3 inches, respectively
(Figure 2). (Age VIII is based on a sample of only five fish, so little
reliance can be placed in the calculated difference at that age.) The
greatest annual growth of both males and females, 5.7 inches, occurred
in the second year of life (Tables 3 and 4, Figure 2).
The validity of back calculating growth is confirmed by the similarity
between measured lengths at capture and calculated lengths for fish of
the same age groups (Table 5). Most of the fish were collected in the
fall, after most of their year's growth was completed, but before the
annulus was formed. Therefore, measured lengths were compared with
calculated lengths of fish a year oldei-.
The discrepancy between the third year growth increments found by
the two methods was caused by biased sampling of age I-|- and II-j-
fish. Age I fish were collected in August, before their annual growth
was completed. Moreover, most age II fish were from the upper half of
+ 15
FIGURE 3. Percentage deviation from the mean annual growth Increment of striped bass.
AGE AND GROWTH OF STRIPED BASS
288
tlie leiiyth distribution, siiu-c fish in the lower half of the leiiyth distri-
bution were protected by the 16-inch minimum size limit when these
samples were taken.
Annual Fluctuations in Growth Rate
To determine annual iiuctuations in the growth, the percentage de-
viations from the mean annual increment were calculated according to
the method described by llile (li)41), using the mean annual increments
in Tables 1 and 2. All age groups were weighted equally. The period
1949 to 1951 was eliminated from the calculations because the age
groups VII, VIII, and IX are poorly represented.
The percentage deviations for the 1952 to 195() pei'iod are shown
in Table 6 and Figure 8. Growth was slow in 1952, and faster than
average the next three years, with the maximum for the period oc-
curring in 1953. From 1953 to 1956 there was a steady decline in
growth.
These data show^ that there are annual fluctuations in growth. How-
ever, so few years of data are involved that the significance of the
18-12
17- 8
16-4
15-0
13-12
12
o
-z.
3 10-
O
Q 7-
^ 3-
UJ
5
2-
/
/
/
s
yr.
J
J
Syr.
7yr.
6y
,
/
5yr.
--/
/
4yr.-
-/
3yr. -
-j
y
2yr. -
lyr
. ____,
1
5 10 15 20 25
FORK LENGTH IN INCHES
FIGURE 4. Length, weight, and age relationship of striped bass.
30
35
284
CALIFORNIA FISH AM) GAME
Unetnations cannot be determined. ^Moreover, data to indicate the causes
of tlie tiuctnations are not available.
Length-Weight Relationship
The lenp'th-weight relationship is described by the equation log
W = —2.1. 398 + 3.0038 long L, and this line is plotted in Figure 4. The
annual weight increments are shown in Figure 5. This relationship is
similar to the results of three other striped bass length-weight studies
(Clai-k, 1!)38; Merriman, 1941; Morgan and Gerlach, 1950).
Comparisons of Growth
Previous striped bass growth studies have been made on the At-
lantic Coast (Pearson, 1938; Merriman, 1941; Tiller, 1950; Vladykov
and Wallace, 1952; Stevens, 1957), and also in California (Scofield,
1931) and Oregon (Morgan and Gerlach, 1950). Reported growth rates
40
05
U
O
z
O
liJ
UJ
cc
o
30
20
o
UJ
<
z
z
<
/
\
/
\
^
/
\
/
\
/
/
1
r
/
/
1
/
1
i
i <
\ e
> (
5 "i
' £
\ 9
AGE CLASS
FIGURE 5. Annual weight increment of striped bass.
AGE AND GROWTH OF STRIPED BASS
285
oo
•<
IM
>o
O
O
<N
00
05
d
d
CO
(N
I— 1
lO
00
t^ ^
N
05
00
00
1> OS
00
c-a
d
CD
00
CO W lO
f
CO
OS
_^
t^
to CD t^
CO
d
^
'm
C<1 IM IN
(N
o
o
^ — '
CO
0)
r— 1
CO
Ot;
-f -* C»5 lO
lO
CO
IM
' '
to
-t< ^ 'f lO
TtH
d
c-i
"o
(M CM (M tM
IM
t-
c3
a;
"O
'o
Oi
t^
lO o cs r — 1<
CO
Oi
0)
lO
Ol (>) -H rt IM
0-1
o
IM
(N C-4 !M (M O)
(N
-tj
03
^j
-1<
bli
CO
o
fl
lO lO CO --^ -r t^
-r
(M
0)
•t
03 05 O: Oi 00 05
d
d
•i<
13
1— I rH I— 1 i-H .— I I— 1
T— 1
(D
-(-:*
^
O
-t
03
00
>o
o
o o 3-. ^ o-j 00 -t<
C^l
o
-V
CO
ec
O IC iO lO -t t <o
lO
d
lO
in
t~
00
lO ■* 03 O; (M lO 00 O
00
o
1^
CO
(N
0005000100
d
d
lO
lO
-f
00
^ O —1 1-0 CO 03 O -H
'-^
o
T-l
CO
.— 1
-t-t'+it-tCOrffCO
-t
o
-t
03 - — '
^ ■S
(M-l<-fOC)t^O'^
OOJlMiOCOt^CT-H
r-irt<N(MO)(N(NCO
o ^
lO
a
00
^
^•5
rHOOSOlO^COlN
CO
s
o^
CO O: 00 CO (M •-!
1— 1
Z
1— ft— )J>^^-<^-l)— IK>I
M
C
2
"o
i2
a
T3
c
3
o
a
c3
s
M
3
0)
0)
Ml
o
o
"3
»*H
_c
-»1
o
o
,
a>
^
03
-rt
W)
o
3
CO
3^
^
d
tC
o
03
o
-^
c«
Ul
0)
Ul
T3
03
T3
^
X!
o
cS
02
<5
a
3
286
CALII'OKMA nsu AND GAME
oo
■a
QQ
•Ct
0}
1
CO
t~
/
0>
O!
in
t~
05
IN
cj
CO
d
in
(N
to "O
in
CO
f— (
X
ffC cc
1—1
CO
d
cj
CO
CO
i-H
i-H t^ OJ
■*
^
■n
^
w
Oi Oi Oi
OJ
d
IN
'Jl
(N oq cj
c»
o
_c
'
in
03
00
CI
(*-<
CO -H lO 05
05
CO
lO
^^
o
o t- t~ o
CD
d
CO
"o
IM <N (M (N
IN
^
ca
05
o
Cl
Tf
t^ t> 00 t~ CO
^
CO
r~
t3
■o
C^ CO -t ^ CO
CO
d
co'
0)
(N !N C^ (N Ol
o
-fj
aj
+j
M
CO
CO
C
1^ -H t^ to CO t^
l>
^
1— <
0^
-f
03 cn o o o t^
03
o
•*
■a
^ .-H C-1 C^l C^ rt
0)
-VJ
_2
05
s
O
CO O >0 -f t~ Tfi 03
CO
o
lO
o
CO
■o lo in to ic CO CO
■o
d
•n
lO
00
03
ii5iOO;Cn(NOCOO>
00
o
t^
o
C-l
OOiCaOl'-O'MOO
oi
d
in
in
TtH
Oi
Oi^O-iiO-iOOO
'-'
o
^
CI
co^-i<T)<Ti<f>nco
-P
d
"*
a ^
^ "S
Tf O lO Oi C7i CO -^ 05
1
■^"o
CO o CO lo 00 o CO CO
Pm^
a c
.-H CI M (M C>) CO CO CO
o 'O
in
s
02
r\
_
CI
-i< o 0-] -f CI 00 CI CO
5
" lO 00 CI -H
z
Hs>>^::^s><
KH M K* K^ „ ,_,
5
M
a
-2
j3
2
"o
a
T3
a
2
fl'
c3
S
M
3
4)
s
£
■a
_13
<
o
o
,
0)
u
c3
J2
bD
o
3
09
>
T3
CI
e
03
tc
o
eu
tJ
0)
in
73
O
till
03
>
"1
s
3
AGE AND GROWTH OP STRIPED BASS
287
are seen to be p-enerally similar to those found in the present study
(Table 7), with the exception of the work of Stevens (1957). However,
the latter study is not completely analogous, since it involved the land-
locked population in Santee-Cooper Reservoir.
Tlie ]n'eseiit study shows that there has been a sif2:iiifi("ant increase
in the growth rates of the California bass since the work of Scofield
(Tables 3 and 4). This increase occurs after the second year, and it is
greater in females than in males. For females, the greatest difference
is 2.8 inches at six years of age, while for males the greatest difference
is 2.3 inches at both six and seven years of age. This represents ap-
proximately a 10 percent increase in length and a 25 percent increase
in weight.
TABLE 3
Comparison of Growth of Male Striped Bass in 1930 and 1957-58
Mean calculated fork length
Mean
"annual growth
1930
1957-58
Differ-
ence
between
1957-58
and
1930
1930
1957-58
Differ-
ence
Year of life
Num-
ber of
fish
Length
(inches)
Num-
ber of
fish
Length
(inches)
between
1957-58
and
1930
1.
35
35
35
35
34
18
12
4.2
9.9
14.6
17.5
20.3
22.2
24.1
385
385
354
164
75
36
16
5
2
4.1
9.8
15.2
19.4
22.3
24.5
26.4
28.2
30.0
—0.1
—0.1
*-|-0.6
*-|-1.9
*-f-2.0
*-|-2.3
*-|-2.3
4.2
5.7
4.7
2.9
2.4
1.9
1.9
4.1
5.7
5.4
4.2
2.9
2.2
1.9
1.8
1.8
0 1
2
3 - --. .- .-
0
+ 0.7
+ 1.3
+ 0.5
+ 0.3
0
4
5
6 --- .
7
8 -
9
* statistically significant increase in growth.
TABLE 4
Comparison of Growth of Female Striped Bass in 1930 and 1957-58
Mean calculated forlv lengtli
Mean annual grow tli
1930
1957-58
Differ-
Differ-
ence
between
ence
between
Num-
Num-
1957-58
1957-58
ber of
Length
ber of
Length
and
and
Year of life
fish
(inches)
fish
(inches)
1930
1930
1957-58
1930
1
43
4.2
295
4.1
—0.1
4.2
4.1
—0.1
2
43
9.7
295
9.8
+ 0.1
5.6
5.7
+ 0.1
3
43
14.6
281
15.3
*+0.7
4.8
5.5
+ 0.7
4
43
18.1
131
19.7
*+1.6
3.5
4.4
+ 0,9
5
43
21.3
49
23.4
* + 2.1
3.2
3.7
+ 0.5
6
33
24.1
25
26.9
* + 2.8
2.7
3.5
+ 0.8
7
21
26.8
13
29.4
* + 2.6
2.7
2.5
—0.2
8
5
31.5
2.1
9 -__ -__ -
3
32.9
1.7
* statistically significant increase in growth.
288 CALIFORNIA FISH AND GAME
TABLE 5
Comparison Between Measured Fork Lengths of Striped Bass Collected in 1957-58
and Calculated Fork Lengttis
Males
Females
Mean length
Mean calculated
Mean length
Mean calculated
at capture
length
Age
at capture
length
(inches)
(inches)
group
(inches)
(inches)
4.1
I
4.1
8.6
9.8
II
8.6
9.8
16.2
15.2
III
16.4
15.3
19.4
19.4
IV
20.0
19.7
22.4
22.3
V
23 . 5
23.4
25.0
24.5
VI
25.9
26.9
26.2
26.4
VII
28.9
29.4
27.7
28.2
VIII
30.6
31.5
29 . 0
30.0
IX
33.4
32.9
31.1
33.9
TABLE 6
Percentage Deviation from the Mean Annual Growth of Striped Bass, 1952-1956
1952
1953
1954
1955
1956
— 1.8
— 17.1
—9.5
+ 2.7
+ 7.8
+ 5.3
+ 3.6
— 1.9
+ 0.9
—1.4
+ 2.0
+ 0.3
—1.3
Females
—8.0
—4.7
TABLE 7
Growth of Striped Bass in Various Waters, Sexes Combined
LENGTH IN INCHES
Merriman
(1941);
mean
calculated
Morgan
Present
fork length
and
study,
Schofield
Pearson
to 4 years,
Gerlach
Stevens
1957-58;
(1931);
(1938);
mean fork
(1950);
(1957);
mean
mean
fork
lengths
mean fork
mean
calculated
calculated
length
of age
lengths
calculated
fork
fork
frequency
classes
of age
total
Year of life
lengths
lengths
distributions
5 to 9 years
classes
lengths
1.. ..
4.1
9.8
4.2
9.8
4.0
10.0
4.9
9.3
8.5
2
15.7
3
15.3
19.6
14.6
17.8
15.0
18.5
14.4
17.7
14.5
19.0
19.8
4
22.9
5
22.9
20.8
20.9
22.7
25.8
6....
25.7
23.2
24.0
25.0
28.5
7
27.9
25.4
27.0
27.3
30.2
8
29.9
32.3
29.5
32.3
28.8
30.0
9
AGE AND GROWTH OP STRIPED BASS 289
There are many possible eaiisos for this increase in growth rate, but
the available data are insufficient to determine which ones are respon-
sible. One of the most logical explanations is that the competition for
food has decreased, due to the decline in the numbers of sti-iped bass
during this period. This decline in the bass population is shown by the
marked decline in catch per unit of effort in the stri])ed bass sport
fishery (Calhoun, 1953; Ryan, 1959; and unpublished data).
MANAGEMENT APPLICATIONS
The results of the present study are pertinent to an evaluation of
llic increase in the minimum size limit from 12 inches to 16 inches made
in 1956. These results show that Clark's (1938) finding that bass double
their weight between 12 and 16 inches is still valid. However, the ])resent
study indicates that this growth is now accomplished during a shorter
period of time. Therefore, the present growth rate is even more favor-
able to the increase in size limit than it was thought to be on the basis of
the information that was avaiUU)le wIumi the size limit was changed.
The threadfin shad, Dorosoma pdcnense, was introduced into res-
ervoirs on the Sacramento-San Joaquin river system in 1959, and is
expected to become established in many of the areas now inhabited
by striped bass. This study will be of value in helping to determine
the effect of this introduction on the striped bass population.
SUMMARY
Striped bass collected in 1957 and 1958 were studied to determine
whether significant changes in the growth rate had occurred during
the last 30 years. The growth rate was determined by aging scales and
back calculating the growth. The length-weight relationship was also
determined.
It was found that the growth rate is similar to that found iu Cali-
fornia 30 years ago, and in most other striped bass i)opulations. How-
ever, it does show that there has been a significant increase in the
growth rate of California striped bass between the ages of III and
VII during the last 30 years. This difference reaches a maximum of
about 2.5 inches at ages VI and VII.
No significant changes were found in the length-weight relation-
ship, but, because of the increased rate of growth, the mean weight
of bass at a given age is greater.
The age and growth data from this study are more favoi-ablc for
the size limit increases made in 1956 than the growth data available
for evaluation at that time.
ACKNOWLEDGMENTS
The author wishes to thank Harold K. Chadwick for his guidance
and helpful criticisms, and to acknowledge the assistance of Vincent
Catania, William Kier, and Bruce Eliason, who lidped collect and
process data.
290 CAMFOKMA FISH Axn r; A:\rE
REFERENCES
Callionii. A. .1.
I!jrj3. Stato-wiilc Calit'oniia auulin.i; est iiualcs for l!)."il. ("alif. Fish and Uaino,
vol. 39, no. 1, i)p. KKJ-nS.
Clark, G. II.
103S. "Woisht and a.ue (let cnuiiiat ion of striiit'd liass. Calif. Fish and Game, vol.
2-1. no. 2, iqi. 17(>-1 77.
Hih*. Ralph
1!)4]. Afic and ,i;ro\vth of the rock hass. A nililoiilifcs riiprstris (Rafinesque) , in
Nebish Lake, Wisconsin, ^^'is(•. Acad. Sci., Arts and Let., Trans., vol. 33,
pp. 189-337.
Merrinian. Daniel
1941. Studies on the striped bass (Rocriis snxatilis) of the Atlantic Coast. U. S.
Fish and Wildl. Serv., Fish. Bull., vol. 50, no. 3-"), 77 pp.
Morgan, Alfred R., and Arthur R. Gerlach
19.jO. Striiied Itass studies on Coos Bay, Oregon in 1949 and 19-50. Oregon Fish
Comm., Contrib. no. 14, 31 pp.
Pearson, John C.
1938. The life history of the striped bass, or rockfish, lioccus saxatilis (Wal-
baum). r. S. Bur. Fish.. P.nll.. vol. 49, no. 28, pp. 825-851.
Ryan. James H.
1959. California inland angling estimates for 1954, 1956, and 1957. Calif. Fish
and Game, vol. 45, no. 2, pp. 93-109.
Scofield, Eugene C.
1931. The striped bass of California ( Rocvus Uneutus). Calif. Div. Fish and
Game, Fish Bull. 29. 84 pp.
Sigler, William F.
1953. The collection and interpretation of fish life history data. Pnbl. by W. F.
Sigler and Wildl. Mangt. Dept., Utah State Agric. College, Logan, Utah,
40 pp. (mimeo.)
Stevens, Robert E.
1957. The striped bass of the Santee-Cooper Reservoir. South Carolina Wildl.
Res. Dept., Rept., 21 pp. (mimeo.)
Tiller, Richard E.
1950. A five-year study of the striped bass fishery of Maryland, based on analyses
of the scales. Publ. Chesapeake Biol. Lab., no. 85, 30 pp.
Vladykov, V. D., and D. H. Wallace
1952. Studies of the striped bass, ]\occiis saxatilis (Walbaum), with special ref-
erence to the Chesapeake Bay region during 1936-1938. In: The striped bass,
Bocciis saxatilis, by Edward C. Raney et al., pp. 132-177. Bull. Bingham
Oceanographic Collection, vol. 14, no. 1.
Whitney, Richard R., and Kenneth D. Carlander
1956. Interpretation of body scale regression for coiniiutiug body length of fish.
Jour. Wildl. Mangt., vol. 20, no. 1, pp. 21-27.
THE IMPORTANCE OF THE OCEAN SPORT FISHERY
TO THE OCEAN CATCH OF SALMON IN
THE STATES OF WASHINGTON,
OREGON AND CALIFORNIA'
HENRY O. WENDLER
State of Washington
Department of Fisheries
INTRODUCTION
Commercial tishiny for salmon in the ocean began in the late lJ)th
and early 2()tli centuries when it was found that both chinook (Onco-
rhynchus tshawytscJia) and silver salmon (0. kisutcJi) would readily
take a trolled lure (Van Hyning, 1951). Scofield (1956) noted that
commercial trolling through the 1890 's amounted to little until the
discovery of the mild-curing process (about 1898) following which it
reached quantity production about 1901. Kauffman (1951) stated that
Washington inside commercial troll (>rs gradually turned to more pro-
ductive grounds offshore after 1917. These offshore trollers were ex-
ceedinglj^ important to the economy of many small coastal ])orts and
were instrumental in opening new small boat harbors along the coasts
of Washington, Oregon, and California.
Commercial trolling licenses have shown a general increase after
World War II and especially during the last few years. Pai't of the
increase has been due to the ease in obtaining licenses in some of the
states, regardless of type of boat or gear. Both commercial aiul sy)ort
trolling may be conducted readily from small boats wliicli rc(i\iire a
low original investment. The gear used is comparatively inexpensive.
This manner of fishing, therefore, has attracted many hundreds of
commercial and sport fishermen to wat(>rs adjacent to 1he coasts of the
three aforementioned states.
Sport fishing for salmon in Washington's sounds, bays, harbors, and
rivers also dates back to the late 19th century (Pressey, 1958). How-
ever, it was not until the early 1940's that this salt-watei- sport began
showing signs of becoming one of the more important fisheries of this
state. Scofield (ojJ. cit.) mentioned that salmon trolling was practiced
in California in the early 1880 's by a few sportsmen. Tiie real increase
began after World War II. Prior to 1951, except for the Puget Sound
region, salt water sport catches generally occurred either in oi- just off
the various coastal river mouths during the period when runs of salmon
were expected to enter the rivers on their annual spawning migration.
I Submitted for publication March, 1960. Prepared at the request of the Pacific Marine
Fisheries Commission. Data supplied by the State of Washington Department of
Fisheries, the Oregon Game Commission, the Oregon Fish Commission, and the
California Department of Fish and Game. Figures by Cliffa Corson.
( 291 )
292 CALIFORNIA FISH AND GAME
Prior to 1950, I'datix-ely few sportsmen had fished for sahnoii in the
ocean. The few pioneers in ili(>se areas were generally local people using
small low-i)owered open boats wlio fished 1lie "safe" tides and then
scni-ried lo shore with their catches. The horsepower race which so
i-adically changed llie antomotive field after World War II also af-
fected inaiinfacturers of small boat motors. The use of glass, metal,
and ])lastics has revolutionized the boat building industry. The com-
bination of dependable and powerful motors with larger, more sea-
worthy small craft has permitted the sportsman to travel to offshore
fishing areas that would have been unsafe only a few years ago. These
small craft have tended to outmunber the commercial boats and have
invaded coastal waters that formerly had been fished exclusively by the
commercial troller.
The question often arises in almost any discussion wdth commercial
or sport fishing interests as to the importance of these two fisheries to
the total ocean catch of salmon. The primary difficulty in reaching ade-
quate conclusions has been a lack of the mani)ower needed to make
satisfactory surveys of sport fisheries. The commercial salmon catch for
the three western states is obtained relatively easily since the poundage
of all fish sold must be listed on receipt sheets, copies of which are sent
to the managing agency. The number of fish in the catch can then be
determined by applying average weight factoi-s collected in the field.
The estimation of the catch by sportsmen has always been fraught
with difficulties. Each year the fishery may change either in area fished,
duration of the fishery, or type of lure used. The program of sampling
may be limited in scope because of manpower shortages. These factors,
singly or in combination, may cause sampling errors which in turn
may induce the catch estimate to be too large or too small. However,
each of the states involved with ocean sport fisheries has developed
certain methods to enumerate the catch.
In the sport fisheries two types of boats predominate : the skiff or
outboard kicker boat, and the party or charter boat. The party boats
usually have better angler success because of their greater cruising
range and experienced professional skippers. They also carry consider-
ably more people than the smaller limited-range outboards.
METHODS OF ESTIMATING CATCH BY SPORTSMEN
Washington
Washington does not issue a sport fishing license for the taking of
salmon. The basic statistic used to estimate the sport catch depends on
the area fished and the coverage desired. In and off the mouth of the
Columbia River boat counts taken by the Coast Guard are used in
conjunction with personal interviews as the boats bring their catches to
the landing areas. This particular sampling program is conducted
jointly with the State of Oregon since the Columbia River is the state
boundary line. In the more northern coastal areas charter boat log
books, Coast Guard boat counts, and personal interviews are utilized.
In the extreme northern sector (Neah Bay), boathouse report forms
are used in conjunction with interviews. Through the use of these
methods, sampling intensity has been as high as 30 percent of the boats
fishing in the area (Columbia River Progress Report, August-Decem-
ber 1956).
SPORT CATCH OF OCEAN SALMON 293
Oregon
Oregon requires a sport fishing license for salmon and steelhead and
ntilizos the punch card-interview system coupled with Coast Giiai-d
counts of boats in the areas of fishing to enumerate the catch. Tliis
method has been successful in certain areas where the fishery is not
spread over great distances and a single species predoininalcs in ihc
catch. The Oregon punch card does not differentiate between s])ecies
of salmon. Prior to 1!).j9, it Avas not retpiired to note on the punch card
the number of fish caught if the catch occurred in international
waters. This necessitated interview sampling which may have l)een
sparse because of limited maii]M)wer. By legislative act in 1959, a land-
ing inii)ortation law was enacted which requires that salmon caught in
international waters be noted on the punch card when the fishermen
enter the state waters.
California
California also requires a spoi-t fishing license. Tn this state party
boat ski])pei's are required to send a daily log of their passengers'
catches to the Department of Fish and Game. Spot checks are made
of the accuracy of these reports. In 1955 and 1956 a federal aid project
made a detailed study of party boat, skiff, and other ocean sport
salmon catches, primarily by sampling the landings at various ports.
The figures used in Table 3 were obtained from these sources. In 1955
and 1956 party boat landings represented 65 percent of the total ocean
salmon sport landings. Party boat records were used to calculate the
totals for other years. An assumption, based on observations but not
samples, was used to make these calculations. It was: party boat land-
ings were 90 percent of the total from 1947 through 1950, and 65 per-
cent from 1951 on (Eldon P. Hughes, personal commnnication March
1959).
California also has used a post card survey method to estimate the
trend of sport fishing catches during many of the years from 1936
through 1957 (Calhoun, 1950, 1951, and 1953; Skinner, 1955; and
Ryan, 1959). In this method questionnaires are sent to a random
sample of license holders. Post card surveys are suspect for a variety
of reasons, and in this instance the federal aid study of 1955-1956
demonstrated that in 1956 the post card returns gave an estimate of
the ocean salmon fishery that was nearly three times what it slundd
have been.
OCEAN CATCH OF SALMON BY STATES
Washington
The phenomenal groAvth of the ocean sport fishery in Washington
was further hastened by funds allocated by the Corps of Engineers
for building and enlarging small boat basins. Westport, located about
midway along the Washington coast, was relatively unknown |)ri(»r
to 1950. It is now the center of sport fishing activities and boasts
one of the finest protected boat basins along the coast. Within a few
minutes, fishermen leaving this small coastal town can be in a ])osition
to intercept the salmon runs moving either north or south. The ocean
sport fisheries in Washington appeared relatively minor until 1952
(Table 1, Figures 1 and 2).
294 CALIFORNIA PISH AM) GAME
TABLE 1
Washington Ocean Sport and Commercial Troll Catcties in Thousands of Fish and
Percent Spor* Catch 1947 Through 1958
Commercial catch
Sport catchi
Total fish
Percent sport
Year
Chinook
Silvers
Chinook
Silvers
Chinook
Silvers
Chinook
Silvers
1947...
325
584
6
3
331
587
1.8
0.5
1948---
286
746
6
3
292
749
2.1
0.4
1949.-
291
518
8
4
299
522
2.7
0.8
1950-..
257
551
17
13
274
564
6.2
2.3
1951.-.
331
634
34
15
365
649
9.3
2.3
1952-..
407
843
92
30
499
873
18.4
3.4
1953.--
419
665
46
50
465
715
9.9
7.0
1954---
384
403
71
63
455
466
15.6
13.5
1955---
385
494
84
61
469
555
17.9
11.0
1956-..
295
706
118
140
413
846
28.6
16.5
1957...
359
737
102
192
461
929
22.1
20.7
1958---
270
525
84
145
354
670
23.7
21.6
1 Columbia River spoi t landings have been equally cliviiled between Washington and Oregon and aie ineluded in
part herein.
The ocean sport catch for chinook salmon has ranged from a low of
nearly 2 percent to a liig-h of nearly 29 percent of the total catch
during the years 1947 through 1958. Silver catches have ranged from
less than 1 percent to nearly 22 percent during the same period.
Oregon
Ocean sport salmon fishing in Oregon showed nearly the same mush-
rooming increase as in the State of Washington. Sport fishing occurred
on a minor scale for a number of years in Coos, AVinchester, and Depoe
bays but was negligible until 1955 (Table 2, Figures 1 and 2).
TABLE 2
Oregon Ocean Sport and Commercial Troll Catches in Thousands of Fish and
Percent Sport Catch 1949 Through 1958
Commercial catch
Sport catch'
Total fish
Percent sport
Year
Chinook
Silvers
Chinook
Silvers
Chinook
Silvers
Chinook
Silvers
1949-..
109
173
8
13
117
186
6.8
7.0
1950...
88
164
11
3
99
167
11.1
1.8
1951...
212
279
10
6
222
285
4.5
2.1
1952...
237
353
11
16
248
369
4.4
4.3
1953---
150
278
15
13
165
291
9.1
4.5
1954-..
195
240
17
22
212
262
8.0
8.4
1955.-.
307
267
59
44
366
311
16.1
14.1
1956---
334
449
51
105
385
554
13.2
19.0
1957.--
251
551
79
124
330
675
23.9
18.4
1958-.-
174
195
74
59
248
254
29.8
23.2
SOURCES :
IKCES: Commercial landings from the Oregon Fish Commission Research Laboratory iii Astoria, Oregon.
Sport catch estimates from Dr. John Rayner of the Oregon Game Commission, Portland, Oregon.
' Columbia River sport landings have been equally divided between Washington and Oregon and are included in
part herein.
SPORT CATCH OP OCEAN SALMON
295
f^
CD
O)
o
._■
OJ
ro
^
If)
c£)
r^
CD
rt
»;}•
^
ID
in
If)
If)
in
in
in
in
U-)
O)
(T>
a>
O)
22
0}
en
0^
CD
O)
CD
en
FIGURE 1. KING (CHINOOK) SALMON. Numbers of ocean caught king salmon landed by
commercial and sport fishermen in Washington, Oregon, and California.
296
CALIFORNIA FISH AND GAME
The percent ocean sport catch by species has risen from over 4 in
1952 to nearly 30 in 1958 for cliinook salmon, and from nearly 2 to
over 23 for silver salmon in 195U and 1958 respectively. JSilver salmon
contribnte the major share of the ocean sport catch in this state, aver-
aging nearly 55 percent from 1949 throngh 1958. This relationship
holds trnc in the commercial fishery also.
California
Sport fishing for salmon in California occurs, for the most part,
from Monterey Bay northward. Significant catches are made in Mon-
terey Bay, otf San Francisco Bay, off Fort Bragg, and northward from
Eureka. The fishery first became important at San Francisco which
was and is primarily a party boat fishery. In the other areas the pro-
portion of skiff catches is much higher. (Total landings of sport and
commercial salmon are shown in Table 3 and Figures 1 and 2.)
The ratio of king to silver salmon varies from port to port and sea-
son to season, but for purposes of estimating the numbers of silver
salmon for Table 3 it was assumed that the relationship found in 1955
and 1956 existed from 1947 through 1958. During those seasons 7.4
percent of the total sport landings w^ere silvers.
Of the total salmon catch in California, the catch by the ocean sport
fishery has ranged from less than 1 percent in 1947 to a high of 22
and 21 percent in 1953 and 1955 for chinook and silver salmon re-
spectively. The dramatic increase in landings which occurred in 1951
has fallen off in 1957 and 1958.
KING (Chinook) SALMON
The chinook catches of all states have been combined to indicate
the relative strength of the sport catch along the West Coast (Table
4). AVendler and Jnnge (1957) have pointed out that more than one
TABLE 3
California Ocean Sport and Commercial Troll Catches in Thousands of Fish and
Percent Sport Catch 1947 Through 1958
Commercial catcli
Sport catch
Total fish
Percent sport
Year
Cliinook
Silvers
Chinook
Silvers
Chinook
Silvers
Chinook
Silvers
1947---
610
87
5
0.4
615
87.4
0.8
0.5
1948.--
421
93
11
1
432
94
2.5
1.1
1949.--
400
89
23
2
423
91
5.4
2.2
1950---
430
85
57
5
487
90
11.7
5.6
1951---
416
58
103
8
519
66
19.8
12.1
1952---
474
92
123
10
597
102
20.6
9.8
1953---
490
100
141
11
631
111
22.3
9.9
1954---
771
64
171
14
942
78
18.2
17.9
1955..-
747
56
184
15
931
71
19.8
21.1
1956.--
958
68
163
13
1,121
81
14.5
16.0
1957---
482
89
64
5
546
94
11.7
5.3
1958.--
350
20
65
5
415
25
15.7
20.0
SOURCE: Salmon and steelhead investigations. Marine Resouiees Branch, California Department of Pish and
Game, March 1959.
SPORT CATCH OF OCEAN SALMON
297
8
7
Q
Ll)
O
X
CO
3
o
X
I-
o 2
UJ
01
Q
z
X I
0
SILVER SALMON , OCEAN LANDINGS
_L--A= ---k =^^^.^i!^ii!zi±ri2
K
CO
0^
O
—
OJ
fO
^
in
U)
N-
00
^
"^t-
^
If)
to
in
lO
lO
in
in
in
in
0^
(T>
m
0^
a>
CD
<T>
en
0^
a>
a>
a>
FIGURE 2. SILVER SALMON. Numbers of ocean caught silver salmon landed by commercial
and sport fishermen In Washington, Oregon, and California.
298
(•.\lill''()KN'l.\ I'MSII .\.\1) (lAME
A'car class ciilcrs the calch of both ocean li'oll and sport lislicrics in a
^'ivcn year. Hence, a inovinji' avera^'c c()inl)inin<i' a1 least two years was
used, not withstandinL;' the fact that the sport fisheries ojx'i'ati' on two,
three, and ])ossibly four year classes.
TABLE 4
Washington, Oregon, and California Combined Ocean Ctiinook Salmon Catches in Thousands of
Fish and Percent Catch by Fishery, 1947-1958
CoMiinercial
eatfh
lOstiniated
.sportr catch
Total
landings
Percent
Combined years
Commercial
landings
Sport
landings
1947-48.
1,642
1,507
1,575
1,734
2,077
2,177
2,409
2,789
3.02()
2,679
1,886
28
56
124
232
373
428
461
586
659
577
468
1,670
1,563
1,699
1,966
2,4,50
2,605
2,870
3,375
3,685
3,2.56
2,354
98.3
96.4
92.7
88.2
84.8
83.6
83.9
82.6
82.1
82.3
80.1
1.7
1948-49
3.6
1949-50 . -
7.3
1950-5 1
11.8
1951-52 .
15.2
19.52-,53
16.4
1 953-54
1 954-55_
195.5-.56
16.1
17.4
17.9
1956-57
17.7
1957-58
19.9
Table 4 indicates that the ocean sport catch of chinook salmon is
approacliinii' ^0 percent of the total catcli. It was pointed out previously
that both ()re«i()n and Washington sport catches have approached or ex-
ceeded one-fourth the total ocean catch in these states. However, Cali-
fornia sport catches werc^ low in I!).")? and 1!)58, which held the total
percent catch for all states combined at a lower level.
SILVER SALMON
The annual catches of silver salmon ha\e been totaled in Tal)l(> ."). Tn
this case individual years have been used since the j^'reat majority of
the silver salmon landed are in their third year.
TABLE 5
Washington, Oregon, and California Combined Ocean Silver Catch in Thousands of
Fish and Percent Catch by Fishery, 1947 Through 1958
Commercial
catch
Estimated
sport catch
Total
landings
Percent
Year
Commercial
landings
Sport
landings
1947
1948
671
839
780
800
971
1,288
1,043
707
817
1,223
1.377
740
3.4
4
19
21
29
56
74
99
120
258
321
209
674.4
843
799
821
1,000
1,344
1,117
806
937
1,481
1,698
949
99.5
99.5
97.6
97.4
97.1
95.8
93.4
87.7
87.2
82.6
81.1
78.0
0.5
0.5
1949 ---
2.4
1950
2.6
1951
1952
2.9
4.2
1953 --- -
6.6
1954
12.3
1955
12.8
1956
17.4
1957
18.9
1958
22.0
SPORT CATCH OP OCEAN SALMON
299
20
J
/
COMBINED
y
OCEAN
;^
/^
SPORT CATCH
/
o 15
<
<
Of^
7
2 10
if)
f
1
f
PERCENT
Ul
jt
J
.u^
^
0
G—
^
/^
SILVER
SA
_M0
N
0}
00
0^
o
in
CD
lO
CD
CO
in
en
ro
in
in
cr>
in
in
CD
CD
in
CD
in
CD
en
in
CD
CAUGHT
en O
(
^
^
^
--
/
J
/
1-
2 10
CO
/I
H
/
PERCENT
en
/
/
>
/
n
(
^
KING(CHINOOK) SALMON
1 1
c»
CD
o
CO
ro
^
in
(D
N-
00
•^
t
in
in
in
in
in
in
in
in
1
in
1
1
00
CD
o
CM
ro
^
in
CD
r-
'^r
rf
^
in
in
in
in
in
in
in
in
CD
CD
0}
CD
0)
CD
CD
0^
<D
CD
0^
FIGURE 3. GROWTH OF THE SPORT FISHERY, Combined Washington, Oregon, and Cali-
fornia sport catches of ocean caught salmon expressed as percent of the total ocean landings.
The king salmon landings have been smoothed by a moving average of two years.
300 CALIFORNIA FISH AND GAME
It may be obsci'ved that llic sport catch of silvers is presently ex-
ceeding 20 percent of the total ocean catch. Prior to 1953, the silver
salmon sjiort catcli was Diiiior in almost all statics when <ir('ater em-
piuisis was placed on catcliiny the largei- chinook salmon. However,
with the advent of the "mooching" method of fishing which uses
herring for bait, and the earlier-season fishing, silver salmon were
canght in largei- numbers. This, coupled with greater immbers of fisher-
man trips, makes the catch of this species by sport gear an important
seofment of the harvest.
o^
SUMMARY OF COASTWISE SPORT CATCHES
The ocean sport catch of both chinook and silver salmon has increased
phenomenally over the past 10 years and is presently accounting for
over 20 percent of the total catcli. There is some indication that the
percent sport catch may be stabilizing on chinook salmon. The sport
fisherman is extending his season in time and is tending to move into
the area that normally was fished only by the commercial troUer.
LITERATURE CITED
Calhoun, A. J.
19r)0. California angling oateli records from postal card surveys, 1936-1948, with
au evaluation of postal card uonresponse. Calif. Fish and Came, vol. 30,
no. 3, pp. 177-234.
1951. California statewide angling catch estimates for 1949. Calif. Fish and Game,
vol. 37, no. 1, pp. 69-75.
1953. Statewide California angling estimates for 1951. Calif. Fish and Game, vol.
39, no. 1, pp. 103-113.
Kauffman, Donald E.
1951. Research report on the Washington state offshore troll fishery. Bull. I'ac.
Mar. Fish. Conim. 2, pp. 77-91.
Pressey, Richard T.
1953. The sport fishery for salmon on Puget Sound. Wash. Dept. Fi.sh. Res. Pap.,
vol. 1, no. 1, pp. 33-48.
Ryan, James H.
1959. Calif, inland angling estimates for 1954, 1956, and 1957. Calif. Fish and
Game, vol. 45, no. 2, pp. 93-109.
Scofield, W. L.
1956. Trolling gear in California. Calif. Dept. Fish and Game, Fish Bull. No. 103.
Skinner, John E.
1955. California statewide angling estimates for 1953. Calif. Fish and Game, vol.
41, no. 1, pp. 19-32.
Van Hyning, Jack M.
1951. The ocean troll fishery in Oregon. Bull. Pae. Mar. Fish. Comm. 2, pp. 43-76.
Wendler, Henry O. and Charles O. Junge
1957. The effect of the ocean sport fishery on the total ocean catch of chinook
salmon (Wash. only). Wash. Dept. Fish, unpublished report on file at
Seattle, Wash.
Washington Dept. of Fisheries
1956. Columbia River Progress Report, August-December. Unpublished report on
file at Seattle, Wash.
TUNA TAGGING IN THE EASTERN TROPICAL
PACIFIC, 1952-1959^
C. E. BLUNT, JR. and JAMES D. MESSERSMITH
Marine Resources Operations
California Department of Fish and Game
INTRODUCTION
The California tuna industry is the most important fishery industry
in the state. It depends primarily upon Pacific yellowfin tuna (Neo
fhimnus macropterus) and skipjack (Kaisuwonus^pelamis). These two
compose a single fishery extending from California to Chile, and are
exploited by large tuna clippers and purse seiner-s based in Southern
California. The fishery reached an all-time high in productivity in
1950 when over 150,000 tons valued at over 45 million dollars to the
fishermen were landed. Because of the value of this fishery to the econ-
omy of the State, the Department of Fish and Game has gathered basic
data pertinent to its management.
One of the fundamental phases of any fisliery investigation is the defi-
nition of the stock or stocks under exploitation. The southerl}^ expansion
of the tuna fishery into northern Peru in 1950-51, central Peru in 1953,
and northern Chile in 1957 has increased the need to define the stocks
that support the industry. Do tlie tuna taken from these areas con-
stitute a single stock of fish, a stock that does not intermingle with tuna
from important fishing areas off Central America and Baja California?
Tagging offers the most direct method of solving this problem.
The first successful method of tagging tunas Avas de\eloped by in-
vestigators of the California Department of Fish and Came in 1952.
The tags, nev7 in concept, consisted of a piece of polyvinylchloride
plastic tubing looped through the flesh immediately posterior to the
second dorsal fins and were developed during two field trials. Results of
the first and part of the second field trial Ave re summarized by Wilson
(1953).
His report described in detail the nine tag ideas devised for the first
field trial and the three tags modified from them for use in the second.
Sinee the early success Avitli ])lastic tubing the California "spaghetti"
or "loop tag" has been used by investigators throughout the United
States. It has proven quite versatile, and in Califoi'iiia has been used
successfully on several species of salmon (Oficorliy]icJnis spp.), steel-
head rainbow trout (Salmo f/airdncri (jairdneri), California yelloAvtail
(Seriola dorsalis), kelp bass ( Paralahrax clathratus), California halibut
(Paralichthys calif ornicus), sturgeon (Acipe'user transmontanus and A.
medirostris) and mauA' others.
1 Submitted for publication January, 19G0.
(301)
3—17250
302 CALIFORNIA FISH AND GAME
The purpose of this report is to present the final results of the second
field trial fi-om October, 1952 through April, 1954, and results of the
regular tuua tagging program commencing in May, 1954 and termi-
nating ill iMay, 1959. Previous to our initial tagging experiments,
little concrete information was avaihible concerning migrations, growth,
and po])ulatioii units of tuna that sujiport the eastern Pacific fishery.
Information obtained from our tagging program will be of value to
other governmental agencies investigating them.
THE SECOND FIELD TRIAL
Tags Used
Information obtained from the first field trial was used in the de-
velopment of three tags (Types E, F, and G) tested during the second
trial.
Type E was constructed of a three-inch piece of No. 20, white, XTE-
30 Fibron polyvinylchloride tubing. Upon this the "return" legend
was inscribed in black vinylite ink manufactured by the California
Ink Company, Los Angeles, formula number 104N5A2. The legend
tubing was then drawn into a 12-inch piece of larger tubing, No. 14
XTE-30 colored transparent Fibron. A piece of Type 302 stainless
steel wire was next drawn through the whole unit and each end bent
back one-quarter inch. The tubing ends Avere then heat-sealed with an
electric iron. AVhen applied to the fish the ends were twisted together
(Figure 1).
Type F w^as similar to Type E except that 27-pound-test braided
nylon fishing line w^as run tlirough the assembly in place of the stainless
steel wire. The ends of the fishing line were tied in a square knot when
applied (Figure 1).
Type G was constructed of 12-inch lengths of No. 14 XTE-30 trans-
parent Fibron polyvinylchloride tubing. Through this was run a 19-
inch piece of No. ' 20, "white, XTE-30 Fibron tubing. The "return"
legend was printed on the center of the inside tubing. To secure the tag
the tubing ends were tied in a figure-eight knot drawn tight against
the ends of the outside jacket and neatly trimmed (Figure 1).
Plastic materials for all three tags were manufactured by the Irv-
ington Varnish and Insulator Company, Irvington, New Jersey. The
outside and inside diameters of their No. 20 tubing are .066 and .034
inches respectively. Size No. 14 tubing is .098 inches outside diameter
and .066 inside.
Early in the second field trial evidence began to accumulate indi-
cating that Type E should be abandoned. Difficulty of construction,
bulkiness, and low return rate all combined to cause its removal
from the field trial. We felt that its heavy weight W'Ould cause abrasion
to the finlets ; and furthermore, a number of Type E tags placed on
yellowtail had untwisted (Collyer, 1954).
Types F and G were shortened after a number of recoveries during
the second field trial made it increasingly apparent that they were too
long. Type F was shortened to nine inches and the outside jacket of
Type G to 10 inches.
TUNA TAGGING
303
Techniques
All of the tags used in the second field trial were applied l)y means
of hypodermic-like needles made from stainless steel tubing. Tlic inside
diameter of the needle was such that the end of the tag rode secure
inside and was carried through the flesli when the neetlle was inserled
into the fish. After removing the needle, the tag was pulled through,
centered, and the ends secured.
TYPE E
TYPE F
TYPE G
FIGURE 1. Tag Types E, F, and G used in the second field trial.
304 CALIFORNIA FISH AND GAME
One of the major jn-obloms inherent in tagging tunas is to remove
the fisli from the -water and affix the tag and return it to the water
before a death spasm takes place, liesults of the first field trial demon-
strated that with careful methods some of the tunas would survive. All
initial work was done aboard the department's research vessel N. B.
SCO FIELD where sufficient help, space and facilities were available
for experimentation. During the second field trial much of the tagging
was done aboard commercial tuna clippers, a very satisfactory and eco-
nomical method because of the fine cooperation received.
We had found from experience that at least two men are needed to
tag tuna etficientlj' aboard commercial clippers. The tagger and his
sponge-rubber-lined tagging cradle should be located near the stern on
the starboard side away from the fishermen in the racks on the port side.
The second man usually fishes from one of the stern racks and is able to
swing fish gently around to the tagger. The tagger then quickly
affixes the tag, measures the fork length of the fish and releases it into
the water. Records are kept on plastic sheets on which tag numbers
were entered in advance.
Results
During the second field trial 4,204 yellowfin tuna and 2,839 skip-
jack were tagged (Table 1) throughout the tropical commercial fishing
area, with the majority released off Baja California and South America.
Attempts were made to test tag Types F and G by tagging in alternate
lots of from 5 to 15 tags each. Because of numerous problems encoun-
tered in tagging at sea and poor availability of materials, it was not
possible to alternate types completely until the latter part of the trial.
In order to compare recovery rates of Type F and G tags, the data
used in Table 1 were resnmmarized to include only those cruises on
which both types were used (Table 2). Recoveries favored the Type
G tag for both yellowfin tuna and skipjack. A Chi-square test showed
significant differences in returns for both vellowfin tuna and skip-
jack (P<. 05).
The apparent superiority of the Type G tag, as used in the second
field trial, was probably due more to its greater visibility than to basic
structural ditferences, since Type F tags have held secure on alba-
core migrating across the Pacific during periods of liberty up to 325
days (Ganssle and Clemens, 1953, Blunt, 1954). Most of the Type F
tags used during the second trial had to be constructed of clear poly-
vinylchloride tubing, (the only material available) giving them a lower
A'isibility factor than the Avliite Type G.
On the basis of the second field trial Type G was selected as the
most efficient and a full-scale tagging program was undertaken.
MODIFICATIONS AND EXPERIMENTS SINCE SECOND FIELD TRIAL
Material
Mar/c/ng Ink and Tag Construcfion
Previous to our initial tagging experiments in 1952, an ink satis-
factory for marking vinylite plastic had not been formulated. With the
manufacture of vinylite ink. Formula 104N5A2, it was possible to
inscribe an apparently resistant legend and number on each tag. The
TUNA TAGGING
805
CO
1
<S
2 '^
o
o
1 1 1
■* 1 1 1 1
1 o 1
1
1 1 1
CO 1 i 1 ■
1 1 1 1 1
1 CO 1
1 »— 1 (
1
CO
1 1 1
(Mill!
' u '
'
>> ♦^
o
^ 3
CO
(N
T— 1
1
1 1 1
1 1 1 ■ (N
1 1 00
,
1 1 1
1 . 1 1 lO
. 1 CO
T3
c £
1 1 1
1 1 1 1 d
1 1 l-H
'
U oj
" >
ll
-^
^
o
.s
'a
■ji
o o o
1^ O 1 O t^
o 00 00
f-H I— I
lO
IN
1}
11
1
o 00 cc
CO —1 1 CO 1^
00 -H 03
03
■^ lO 05
o 00 1 m CO
03 rt O
J2
,-1 1 .-1 CO
rt .-H CO
oo_
0) t;
I— t f-H
i-T i-i"
c4'
^ 0)
S M
S bO
3 03
Z -^
Tt< 1 1
OS 1 1 CO 1
O) OO 1
1
lO ■ 1
IN 1 1 CO 1
t^ t~ '
(M 1 1
a ' '
CO CO 1
1 I 1
1
00
CO
CO
(N
Q °
1 1 lO
1 r . 1 O
1 t 00
1
1 1 ira
1 ( 1 1 t^
1 i IN
1
TJ
1
^ £
1 1 d
1 1 1 1 o
1 1 w
1
4) 0)
? >
11
a
tH
«a
1
^
CO O CO
CI o o --1 CO
a: ^ CO
^ CI
CO
>^
Is
•* 03 CO
■* (N IN •* (N
O Ol 03
s
CO o -^
to ■* (N CO tD
Tt< >o o;
o
L-i
C^ CO lO
0_ IN lO 0O_^
lO CJ t^
<N
q;> -d
.—I I— 1
^^ < — i
■*'
Xi ^
G W)
C hi
3 03
:z;*^
'S
^
+J
o
o
"o
o
1 1 13
1 1 1 1 "3
1 1 "3
T3
C
1 1 -^
, > \ i -^^
1 1 -^
^
H
1 1 o
1 1 -*^
< Xi
Clear...
Blue_._
Red
Yellow.
Subto
, < o
1 1 +^
0) ."K 3
_3 J3 C/3
03
o
s
a
w
fe
o
H
306 CALIFORNIA FISH AND GAME
TABLE 2
Releases and Recoveries During Second Field Trial Using Type F and G Tags
Yellowfin Tuna
Skipjack
Tagged
Recovered
Tagged
Recovered
Tag type
Number
Number
Percent
Number
Number
Percent
F
G
1,844
1,799
9
23
0.49
1.28
1,335
1,309
7
18
0.52
1.38
legend proved adequate when protected by a transparent outer jacket
and placed at the center of the tubing (that part embedded in the
fish) to prevent fading.
MidAvay through the regular tagging program it was felt that re-
moval of the jacket from Type G tags would simplify them and in-
crease tagging speed. This Avas done in 1956 (Cruise 56S1 Table 6)
when an ink. Formula 10-1:N5A4, considerably more resistant to light,
became available.
Plastic Tubing
Shortly after the onset of the regular tagging program it became
evident that the viuylite in recovered tags had lost some of its flexi-
bility. Manufacturers indicated that this probabh' was caused by the
leaching out of the plasticizer, the chemical component in viuylite
responsible for softness and flexibility. This partial loss of flexibility,
however, did not appear to have affected the efficiency of the tags.
Examination of numerous tags on fish that had been at liberty for
periods between one and two years, indicated the material definitely
was not brittle, and still retained satisfactoiy flexibility.
Experience with yellow viuylite tags during the early part of the
program indicated the color faded considerably, even while on fish at
liberty for periods shorter than three months. In 1957, an improved
yellow, Resinite X-270-I (viuylite), was put on the market by the
Borden Company of Santa Barbara, California. This material was
somewhat similar to XTE-30 but Avas considerably softer and had been
formulated to retain flexibility longer. Starting in November 1957, all
tags Avere manufactured Avith it.
Methods
Tagging techniques used during the regular program basically Avere
similar to those used during the second field trial (Wilson, 1953). A
rather important innovation in 1954 Avas the placing of a wet burlap
sack or cloth over the fish's head to aid in quieting it during the
tagging.
Tagging needles also Avere modified slightly. During the second field
trial a needle of stainless steel tubing Avitli the end ground to a sharp
hypodermic-like point was used to insert the tag in the fish. The sharp
edges of this needle cut as it pierced the flesh. To alleviate this, a
TUNA TAGGING
:}07
stainless steel rod was forced into one end of the steel tube and then
ground to a sharp rounded point. This solid-point needle eliminated
much of the cutting of tissue during tagging and resulted in reduced
bleeding.
Detection of Tagged Fish
To publicize the tagging program posters in Spanish and English
were distributed throughout the fishing ports and canneries of the
United States, Mexico, and Central and South America.
The natnre of the fishery is such that individual tuna are handled
at least once before being weighed at the cannery, after which there
is at least one additional handling before cooking and canning. Be-
tween the actual removal of the tuna from the sea by the fishermen
and this final process there are numerous additional instances where
tagged fish could be detected by both fishermen and cannery personnel.
Fishermen often notice tagged fish lying on deck before they are
passed into the refrigerated wells for storage. Cannery personnel also
liave returned tags to us that were first observed on fish on a con-
veyor in transit to the cutting and cleaning line.
Despite these many opportunities for recovering tagged fisli it be-
came evident early in the program that a substantial number of tags
were not being detected and thus were lost. Fishermen reported nu-
merous sightings of tagged fish, but due to the arduous and often
hurried working conditions aboard tuna vessels many were never re-
covered— even when personnel were assigned to look for them during
unloading at the cannery. Unknowni to crew members, tagging per-
sonnel "salted" 16 tagged fish in selected storage wells. Of these 16,
only six were subsequently recovered; four by cannery personnel, and
two by fishermen. The other 10 were never seen again. These findings
indicated a high tag loss during handling and processing, but it prob-
ably would have been even higher had we not used some yellow tags
(Table 3). The better recovery rate for yellow tags is likely due to
the better visibility of this color (Lahr et at., 1959).
f^\e\6 Testing
Experiments testing the visibility of different colors were conducted
in 1956 and 1957. Alternating lots (five each) of red, white, and bine
tags were released (Table 4). There was no indication that red or blue
gave improved returns over the standard white tag.
TABLE 3
Recoveries of Tagged Tuna Planted in Storage Wells at Sea
Tag color
No. planted
No. recovered
No. lost
Red
3
7
1
5
1
1
0
4
2
White --
6
Blue -
1
YeUow
1
Totals --
16
6
10
308
CALIFORNIA FISH AND GAME
TABLE 4
Releases and Recoveries of Tuna Tagged During an Experiment Using
Red, White, and Blue Tags
Red tags
White tags
Blue tags
Cruisei
Tagged
Recovered
Tagged
Recovered
Tagged
Recovered
56C3
224
263
304
200
273
5
2
1
1
1
218
265
304
201
257
1
3
2
1
2
219
265
302
196
94
3
56C4
56C5
57C1
57C4
3
5
1
0
Totals
1,264
10
1,245
9
1,076
12
1 See Table 6.
Dart Tag Experiments
Since the early stages of the program dart-type tags had been seri-
ously considered because of their simplicity and speed and ease of
application. It was not until late 1955, however, that we were able to
test them. During an exploratory oceanographie and longline fishing
cruise (No. 55S5), as a part of expedition Eastropic, a total of 72
yellowfin, skipjack, and bigeye tuna was tagged alternately with dart
and Type G "spaghetti" tags. There were no recoveries from these,
probably due to the fact the fish were caught on trolling lines and
released throughout a very large area in the eastern tropical Pacific.
The dart tags had been obtained through the courtesy of the Woods
Hole Oceanographie Institution. Dart tags of various other types were
used in limited quantities in 1957 and 1958 but none M^as recovered.
Yamashita and Waldron (1958) reported good results from an all-
plastic dart tag used in Hawaiian waters in 1957. Recovery rates up
to 13 percent were realized from two lots of about 5,000 skipjack.
In early 1959, we field tested a FT-2 dart tag manufactured by the
Ploy Tag Company of Seattle, Washington. It has a solid dart head
one inch long constructed of Zytel nylon. Attached to this is a six-inch
piece of No. 18, EP-2, yellow vinylite tubing manufactured by the
Borden Company of Santa Barbara, California (Figure 2).
Both yellowfin and skipjack were tagged alternately with FT-2 dart
tags and Type G "spaghetti" tags off the coasts of Peru and Central
America during Cruise 59C1 (Table 5). The dart tag was applied to
the fish with a hollow stainless steel needle. They were pushed about
one inch into the flesh near the posterior portion of the second dorsal
fin base. Skipjack recoveries were overwhelmingly in favor of the dart
tag. Since the tag types were released alternately it is believed the dif-
ferences in recovery rates indicate a lower tagging mortality resulting
from the dart tag. No yellowfin were recovered.
TAGGING RESULTS
Areas of Tagging
Due to the vagaries of fishing it was not possible to release tags in
selected areas. In general, however, the areas exploited by tuna fisher-
men go hand-in-hand with the seasons of the year. During winter, most
TUNA TAGGING
309
CO
-a
O .Si
11
— o
>- oe
"o
a>
■a
0)
L^
o;
>
M
0
K
■^
4)
J3
M
03
ft
-g
03
»
03
1 CO IM Ol t^ lO
_3
1 a>
"OJ
to
tf
-i!
■S.
^
r/j
1
I 1 1 1 t-H Oi
0
till .-H
o
0^
m
tit
K
03
^
^
«
Q
<A
\ ^ ^ r>\ \^ OX
^
1 ■»}<
'Oj
t--
^
i:
OJ
!_
OJ
1 1 1 1 1 1
o
K
CJ
M
CD
i5
^
-H*
s
,j3
bll
ft
t3
02
Cfi
(fl
_ c<i rt rt CO — •
a;
—1 IN -H
03
'aJ
C
«
*^
S
is
0
13
"a!
0)
r"
O
o
1 1 1 1 1 1
1 1 1 1 1 1
«
03
f~.
0)
Q
73
— I ■* (N IN CO "O
_aj
^ C^ i-i
■oS
tf
09
£
<J
of Tehuantepec
ral America
of Panama
dor-Colombia- .
of Guayaquil-.
(North)
v„ *J ^ 03 ^ -
-- C --^ 3 r^ fc-
p ^ 3 o 3 0)
OOO WOCL,
310 CALIFORNIA FISH AND GAME
fishing is conducted in the vicinitj^ of the Galapagos Islands and off
Central and South America. In the spring, fishing increases off Central
America and ]\Iexico and by summer the fleet concentrates off Baja
California. In recent years, substantial tonnages of yellowfin and skip-
jack have been taken during all months off Baja California.
Some yellowfin and skipjack were tagged and released from tuna
clippers in all of the major fishing areas except the Gulf of California.
The Gulf of C*alifornia produces good catches of relatively large yellow-
fin tuna, but they have traditionally been exploited more efficiently by
the purse seine fleet. Due to the limited and sporadic fishing in the
vicinities of Clipperton, Cocos and Malpelo Islands tew tags were re-
leased at these locations.
Though cooperation of the tuna fleet was excellent during the pro-
gram, scheduling of tagging trips was hindered by labor strikes, tieup
of vessels for economic reasons, inability of small clippers to take two
extra men and a shortage of tagging personnel. Despite these hin-
drances an average of four tagging trips was taken aboard commercial
vessels each year. Additional tuna tagging w^as conducted aboard the
research vessel N. B. SCOFIELD in conjunction with albacore and
.yellowtail w^ork. The 39 tagging trips since the inception of the program
are listed in Table 6.
During both the experimental phases and our regular tagging pro-
gram 27,478 yellowfin tuna and skipjack were tagged in the eastern
tropical Pacific. To show these diagramatically, the number of fish
tagged and released in each one-degree square has been listed on the
three charts covering the range of the fishery (Figures 3a, b, c and 4a,
b, c). The number of recoveries, through November 30, 1959, from fish
tagged in each one-degree square has been entered above the number
tagged. Detailed information concerning month and year of tagging
and recovery is presented in Appendices A, B, C and D.
■ty.
^^^
^YELLOW **I8 EP-2 TUBING
SOLID ZYTEL NYLON
FIGURE 2. Type FT-2 dart tag.
TUNA TAGGING
311
OOOOOOOOOOi-iT}<OOOOC-Jrt<OOi-H!>)OOOO^iO
a M
3 03
CI
(£
o
2; 9
3 d
i-HOmo>i-ico(M'*r^T)ioo30'^'Ocooob-oowiocoroO'*'*'raf~
OCTcoca ooo com ■-•M'N'-ioiiri T)<r>.-HO
O CT CO Ca
O 00
CO 'C
- • 00 <N
t^ o
CM
OCOOO-f-f-fOCOiMO'
CCO^C-)TI<OI^OOCOMCO
^•^l^0it^O00O0Ce0-^'-<'-HOl^OC00i05i0'-iO'0<NO00<DO
^ (>< Ct ^ ^ a> (M t» t- (M •* "O O 'M ■* i-H (N
C3
rt
o
to
ON
1-, -*^
ttT3
0)
o
g
'So
03
03
.2 ^
(MMNcococococococO'^tH-* -iiTtiTfTfinioioira'OOtDcocDO
»0 >0 lO »0 lO »C »0 ifO lO lO lO »0 »0 -^ to 'O »0 »0 >0 'O »0 lO to »o >o ic >o to
■w.\,^-.-\~-^^^"^^^-\-^~-^\,io^^^^~\^^^^^^^~^^^-.^-^^^';>
cot^'-H.-it^ioooOT-iooco^'^Oi^'-tOJ^oost^oo-^t^coco
•-H CO'-i— I.-ICO TOlM'-i O-H ^(M,cO'H<MCO^O)r-'^r'
mioo(M'j<totooot^oo-*tD;oi>-ooi-HiNco-q''*02'^eoiOffloooo
1—1 t-l T— I I-H T-H •-»
C^)iM'M(MCOCOCOCOCOCO'*TjiTllTt<Tt<-*'^'*toiOto>OtotOtDtO«50
to to lO to to lO to 'O 'O to to to to to to to to to to to to to to to to to to to
^^^^^~^"^"-^"^"--, ~..\.~\'-^^^^"\"-^^-~.^^^^^^^^~^^^^^~^^-^^
tOt^CDto^-— <i-H«DXtoCOCO'^'-*'*(N(NCOiOCCtOOOaiO'^tO(N'-H
■-H <» T-t Ol rHr-l .-1 CS ^C^lCM-H—lCl
(N'^OOCO'^toCDCDXi-iC^ltoC^OsXCSO'— •(N'MOOOS'-tCOtOt^t*
o o
o o
s y.
Ph C
■" 2
f=5 CO
I I
o3 03
2 S
-<<
c a
CO (»
2.S § g
-o
03 j^
m ^
i-i c
CO o3
o >,
M 03
o3 3
I . — I
13
c3 03
■§
I 03 h
03 ^^
CJ
^ —
O 03
mo
-iS iTr< O O O O
r- .-H .^ .-H ra ra -^
d C O C M m "
a)jHl->Ht:iMt-H^
en CO M-j
- . , o o -^
03 o3 M M 03
O O' g, g.'0
rf ^ ^ ^ o3
OJ ^ MH ^
^ "s "3 13
"s °oo
.« 2 03 03
-— ; 03 •— s '^^
3 O o3 03
oo wm
s ;:3
c^ c^ rt (fl ^
««oo«
a 03
'S 'S
t-< (H
o o
"m "3
oo
o3 03
'ai"S
m«
03
C3 o
■a 'c -S S 2 .2
fi d) CO -t^ *^ CO
^ ?. I— I fl
o3 _ M I
So >
S I 0; 3
,- d ■
C3
•a
O a S
t- ft
03 -g a
o3 0) 03 J5
moo^
03 X
d ^
O o ;3 O
O 03 O O
■p3 03 o3 *S
J5 « =3 t^
"c s
q; 03
bO lo
5^
03.2
Z^ t-
o o t;
£ B «
^ <=; »-3
M 03
^ o
en ?t3
°o
TSO
0(S
_2 CO
■^ s
I "^
■a-S
O bC
^^
o^
.s.->
03 0)
>
SSSooSoooSoo8SSSooSooo||oooo
H W W
K-( I— I HH
fe Ph fin
GOO
ooo
uimm
m w' pa
o .
VH I
fo -
t— I I
Ph wo
f^^pq
Pi
h, H ' *^ < >
^; :z; 2; 2 i Iz;
PI5
t-l H," -< --i
o
, 1—1
H^Hrt
Z Z <^ rO hH hJ
I— I I-H I-H I— I rv,
^j J k4 • H C
ooo«dS
(1h Ph (li Z M ^
w
pp^n
• So
;5>o
o
^ 1-1 h-1
f^ w w
z fe [i(
K oo
woo
a M «3
o
t— I
o
o w , s
PhW >^0
Km JW
;J12
CALIFORNIA FISH AND (!AMK
1
so <_>
CO
01
01
u "0
-^
c r
c
c
CO 0; C<5 0 (N t^
o3 (u
'*' "" io .-1 00 CV
CO
■s fc
(N
C ''
.i!
3 0
0
Is
— lOJt^OOOmiMOJ'MOW >o
flj rrt
— it^lNOO OJ-HiOtDOtO to
J^
00 .-<iO t^WCOOSCO-* (N
-<" r-<" -rf
3 33
^-
t- "O
(N<N(NOCC<M'-iMO>!NO M
fe »
IN CO
;o
=.
1 «
Cl
s
c -*
3
3 S
-^
2; S
fc-.
OsiOC^O-^^OiOTj^t^COCO M
0
a; '^
Oi'Mt^Ci'NCOCOOCCXO ^
"3
-9 a
3 oj
^-
cot^r^i^t^oooooooooOCTi i
C3
if^tO»OiOiOiO»0>0>C'0>0 1
Lh 4)
3 -S
Ol»0C<»O'-''-''OiOC»»OC0 ^
-*-■ C3
V 13
tf
1-H ' '
«)
cDr^t^t»r^t^t^ooooooo5
3
lO «o »o »o >o »o »o 10 »C '^ >o
+5 0)
t; ^
0050C<5-*M'*(NOOOO>0
CS 03
(M (M ^ ^ CO CC '-'
a-w
^"^■^^^"^"^~^>>:> 1
aj
0'H'-i>n>o>-i'-iT)i«5ooco 1
Q
r-f T-H ^
0
c
c
'S
0 0
0
_o
00
ca
S'3
1
1
'3
cS
"S g
0
s
0
0
C
OJ
03
Q.
s-GuIf
Ameri
a
Ameri
tepee _
Ameri
erir.a.
T3
0)
M
0
rt
c
1
'3
C
c-,i C->^ =^-t^ 5 —
Sci
o33a)333<,T
E •-
u
slsl
a-So
Am
a-So
Teh
a-So
tral
-Rev
0 ^
P-i
-3 S
wo-3o»*-.oflcao3^-<
■C -C £ -C 0 'C « '3 '5 ^^
o3a)^(u^(i)nrE;_o.
S S g 23 S i^^-^i
£ S § g g gooowu
o3aj^a)„Oiajii3»3i'i'
lU a3
.2 J2
•o^c^jcO'^toco^c^cO'H
2 S
oooooooooao
u§
:ot^t>.t^t^t^t^00XXO5
»0»^»OtO»0»OiO>0»0»0»0
1 1
do
HH t— 1
fa fa
r.T
1
0
fa
a
■<
LENGER. _
TITUTION.
FALCON..
HERN PAC
HERN PAC
[IE B
PENDENCl
BEVERLY
^NT
0
"^hJMHHf-p^WWh^S
^^IZDHiDtafc'Q'^'J^
t:,ao^.nn^>.<<0
M
0
0
0
M
CO
«
>—
0
>
U
C13 "S
be
& OJ
— at
^-
CO ra
c o
TUNA TAGGING
313
120' 115* 110*
1 1 1 1 1 1 I ' T 3
30
25
20
30
25
20
YELLOWFIN TUNA
■1 TAGGING 1952 - 1959
0, 1959
\
\
\
w
RECOV. THROUGH NOV. 3
NO. RECOV. 188
NO. TAGGED 3713
V
)
+
y
O
GU
^OALUP
E IS.
(1
V
^^
\^
0 ^
4
A
I...
\
O
0 ^
74
-i-N california\
\
3
64
II
232
4
250
v^
\
^
12
240
3 "N
29
V
0
^
2, (.
474^
^
\
2
29
42
57
707
V
V
515
\ ;
1
8
1
119
4
299
4
18
-^
0
13
1
l23
1
46
<.
» 3
305
1
7
0
62
-= 2
13
R E\
mlla
GIGE DC
> IS
k
12
;o*
115- 110*
FIGURE 3a. Yellowfin tuna tag lots by one degree square of tagging ofF Baja California
and the Revilla Gigedo Islands. The number recovered from each lot is indicated over the
number tagged. Recoveries were not necessarily made v/ithin the degree square of tagging.
314
CALIFORNIA FISH AND GAME
eg
•s •- °°
'<n
•
o
CD
•
It)
CO
e
O
0>
e
lO
0>
0
o
o
0
iP
g
0
O
e
0
< 0)
Z lO
^- T
CM
z IS
— <T>
li. —
*
O O
_l z
-1 5
LlI (S
>■ <
t-
/:
01
If
c
>
c
z
I
c
cc
I
1-
>
c
c
u.
cc
x°'^^
t)CM
0
10
CD
0
0
CM
-1-
0
^
o|io
itO|CM'
r
CO
0
in
CO
0
0
o>
0
in
0)
0
0
0
0
in
0
0
0
y.
h
1^
/
> 7"
olj;;
oK
^~^°%
oK
oi;;;
N
tt n ^n
'=;
J
o|S
OJf>-
o|-
) 2
er
i
CVJ
0
-15
vi
>
O
o
LJ
CC
.
o
z
o 2
/:
i.
t
-
n
0|«D
ojw
OJCM
CO
o / X
2^^
0?
oO
0
0 -
V X -I*
I
0
<^\t
Ol-
0
-^
o|S
}
0>
CVl
3
oil-
/
^IS
o|^
o|=
y
;^''
ojS
0
CVJ
10
CM
0
10
/
o|*
o|^
0
'J-
00
o|^
I
o|S
0J5
0
\
Ipis
ojio
0
CVJ
)
oiS
o;2
/ ^
-
0)
O
O lO /
'?<5
o
o
CVJ
*
N
/o
o
0|CM
'^ol-
o|«)
o|(»
•s
^ o|£! y
^X
o|S
o%
o|o
ol-
^o
CVJ
o|S
o|io
M
olt;
o|<o
o «
o|S
.^
V
CVilcM
O|oo
0|<i>
lO
o
CVJ
O
S
/
/
oK
o|io
o|-
(li
f
/^
0|CJ
-12
z
c
►-
.a
!
— ^
c
c
lu
C
c
<
o|^
^VC
,^7
o|*
(J
a
- Q. —
<?
#
I]
0
0
>
u,
a_
•g
•in
•g
•m
-a
c
>. c
> o
O D)
u n
0)
•— (1)
-a -D
c o
o E
u ^
X '^
ID O
O
II
O"' ^
O) 2
O (O
(U
<u ~
o >
3 O
C3" "
^^
c Si,
D
O *"
c i_
o <u
o <u
— -C
*- >
O °
c
3
_0
>-
J3
CO
UJ
o
TUNA TAGGING
315
9
D*
p<^°
80- 75-
70-
5-
0-
10"
15"
20-
°- ° 0
67 7
0
6
0
14
0.
19
2-^
COLOMBIA
359
5*
0-
5'
10'
15"
20*
COCOS 1
;. 0
4
0
S
0
2
~)
0
40
MALPELC
'V^
7
1
21
0
266
0
1
152
1
389
0
4
0
2
0
567
K^
1
446
0
II
n
s
fo'
0
¥
ECUADOR
f
YELLOWFIN TUNA
TAGGING 1952 - 1959
0
1
O
. 0
1
1
GA
LAP
kGOS
IS
-AND
S
i
51
■^
25
545
Ti
A(
RECOV THROUGH NOV 30, 1
NO RECOV, 54
NO. TAGGED 37B6
i)
V
(
\
K
.0.
22
17
256
-\
\
)
\
\
V
\^
"^
--^
\
f\
0
6-(
9
0-
85'
80- 75-
7C
•
FIGURE 3c. Yellowfin tuna tag lots by one degree square of tagging off South America and
tiie Galapagos Islands. The number recovered from each lot is indicated over the number
tagged. Recoveries v/ere not necessarily made v/Ithin the degree square of tagging.
316
CALIFORNIA FISH AND GAME
120'
115'
110°
V
\
I
1 1 1
SKIPJACK
TAGGING 1952 - 1959
J
1^
RECOV THROUGH NOV 30, 1959
NO. RECOV. 105
NO TAGGEO 3821
0
2
S
\
/
o
GUAD
ILUPE
IS
^^
>
V
0
2
\)
0
1
0
0\CA
54 ^
O
o
2
0^
120
LIFORNIA A^
0
17
15
481
240
x^
15
421
2
27
/
■>
0_
1
328
v^
69
27
476
7
169
\,
^^/70
0
67
2
109
1
109
0.
2
0
3
0
50
12
181
2
262
0
• 2
0
• 23
0
143
3
322
° 0
3
REVIL
.LA Gl
GEDO 1
s
^
1 1
\
30
25
_30
-25
20
120*
115°
110'
FIGURE 4a. Skipjack tag lots by one degree square of tagging off Baja California and the
Revilla Gigedo Islands. The number recovered from each lot is indicated over the number
tagged. Recoveries were not necessarily made within the degree square of tagging.
TUNA TAGGING
317
•lO
CM
•o
M
•« '2 •«
e
O
00
0
lO
00
0
c
0)
D
to
0
o
o
0
in
O
O
o
0
o
CO
0
to
CO
0
o
0
lO
0)
•
o
o
•
lO
o
•
o
0)
lO
0)
1
lO
9: 5
w <
(-
o"
lO
/4
^
'olS
o|S
o\-
^
S
O|<0
o|io
vr
'^
^r'
v*
i
o|=
>
o
z
o>
M^ ol
o|-
oia
o
to
to
CJ
^
o|S
o|eB
o|io
o
^ ote
olcg
-IS
o|«>
o|S
- CO-
_ CO.
♦ o
o
-o
o
RECOV. THR
NO. RECOV.
UJ
o
<
6
z
( CJ
1 O *~ /^
/
CVJ
oh
o|o>
\ "^
X
-
(0
-
^^^ o
\
\
J-
o|2>
o|i2
o|-
0|N
/
lO /
i«
o|S
•
J
o|io
oico
o|*
-/
o|fe
o|o
/
o|SI
o|5»
y
o|2
\
1,
°l?
o|!£
(COCO
o|-
o' 1
/
o|-
/
MS
ol-
'X
o|5!
o|S
0|N
f
olS
o|!2
}
o|r-
0|N
/
o|<M
^
^
t
IM
^
o|!2
/
1(0
"J-
o|§
oil
o|S
o|i-
/
/
o|-
w
/
^^
o|-
z
o
J^
^
^
w
0
0|_
oc
UJ
_/(
:>f
o
Q
UJ -
a.
— $
.^r
o
0
<
-J
>
C-H
UJ
•lO
•o
CVI
•m 'o 'lO
0)
c
o
<u
E
o .
>
O M-
y o
0)
JD -'
C M
D
C <D
<U
^ S)
d <u
C -D
<U O
U E
■a >s
C TZ
o iS
KJ Q)
c (u
•5. »
? >"
O <D
»-»- d)
O >
o
0) u
>- <1)
o c^
5; T3
IV
01 O)
CJ
0) -O
c E
O 3
c
>.
-C 0)
O
0_
[a.
'Ji
IT)
J3
ID
o
318
CALIFORNIA FISH AND GAME
85*
80" 75' 70'
S'
i^
0
6
0
2
*i
COLOMBIA
5'
0-
5-
10'
15- I
20-
s ts.
0
2
0
1
0
2
(
20
MA
.PELC
-1
0
4
>
%
I
0
152
r
J
1
250
^
0 ,
36 1
0
48
e:
1
0 0 1
?i
i
"♦,0 ■-■
t
ECUADOR
SKIPJACK
TAGGINfi I9S? - iqsq
5*
0
0°
1
- 0
22
6
852
G«
LAPA
;os 1
SLAN
3S
9
305
16
747
^*1^
-(
''' RECOV. THROUGH NOV. 30, 1959
NO, RECOV. 122
") NO. TAGGED 8105
V
<
X
\
o
114
\ '"
10'
1
59
48
2182
\
2
K
\
15'
^
\
K
\
\
^^
-x^
\
Y
4
142 (
372 (
90*
85*
80- 75- 7C
)•
FIGURE 4c. Skipjack tag lots by one degree square of tagging off South America and the
Galapagos Islands. The number recovered from each lot is indicated over the number tagged.
Recoveries were not necessarily made within the degree square of tagging.
TUNA TAGGING 319
Recoveries of Tagged Yellowfin Tuna
Through November 3U, 1!)5!), 203 of 13,213 tagged j^eHowfin tuna
were returned. They had been at liberty from one to 842 days and
demonstrated straight line movements up to 1,025 miles. To represent
pictorially a summary of tagged yellowfin movements by periods of the
year, fish recovered 75 or more miles from point of tagging were jilof-
ted on charts encompassing the range of the eastern I'aeifie tunas (Fig-
ures 5, 6, and 7). Detailed information for every recovery can be
found in the appendices.
At the northern extremity of tlie fishery all of the within-season
recoveries of fish tagged during May demonstrated a definite north-
ward movement. Two even moved from the Revilla Gigedo Islands to
Baja California (Figure 5a). One of the off-season recoveries (January-
April) was captured in the Gulf of California. Recoveries of fish tagged
during June indicated northerly movements, with one migrating from
the Revilla Gigedo Islands to the mainland of Baja California (Figure
5b). Most of the fish tagged during July also moved north with oidy
four moving south (Figure 5c). Of those moving south, one traveled
from Baja California to the Revilla Gigedo Islands. Fish tagged during
September and October moved southward (Figure 5d).
Movements of tuna tagged off Mexico and Central America were
considerably more spectacular in that several traveled straight line
distances greater than 1, ()()() miles (Figure 6a). All recoveries of fish
tagged in these areas during February, March and April dcnionstrated
northerly migrations. An important feature is the movement of four
yelh)wfin tuna from the vicinity of the Gulf of Tehuantepec to the Gulf
of California, Baja California and the Revilla Gigedo Islands. These
four were tagged in February within a few miles of each other; 1lie
first was recovered in the Gulf of California in May, the second off
Baja California in August, and the third and fourth near the Revilla
Gigedo Islands in October and November. Other significant i-ccoveries
were two fish tagged off Central America which crossed the (!ull' of
Tehuantepec and were recaptured off Mexico. Recoveries of fisii tagged
in June and December appear in Figure 6b. One fish tagged in June
was of particular significance in that it demonstrated evidence of a
migration between the Mexican mainland and an offshore island. The
best information available from the recovery vessel indicates it ])roba-
bly was caught at Clipperton Island, but there is a slight i)()ssibility it
was caught at New Clarion Bank near the Revilla Gigedo Islands.
A yellowfin tagged north of the Galapagos Islands in March moved
to the Gulf of Guayaquil (Figure 7a), and two tagged in October in
the vicinity of the Gulf of Guayaquil moved south to centi'al Per-n.
Those tagged during November and Decend^er indicated an intei-change
between the Gulf of Guayaquil and the 14 Fathom Bank off INmii
(Figure 7b).
D'scussion
From the Baja California tag returns we infer that yellowfin tuna
move north along the coast of Baja California dui'ing May, June and
July. During the latter month some start to move south, and southerly
movements continue through September and October. Also there is an
:{2()
rALIFORXIA FTSll AND OAME
FIGURE 5a. Yellowfin tuna movements of 75 or more miles as shown by recoveries of fish
tagged in 1958. Uncircled figures represent origins of the tagged fish.
interchange of yellowfin between Baja California and the Revilla
Gigedo Islands. Further the seasonal fisheries off Baja California, the
Gulf of California, and the Revilla Gigedo Islands are supported in
some degree by the northerly movements of yellowfin tuna along the
Mexican coast in winter and spring from at least as far south as the
Gulf of Tehuantepec. Recoveries of two fish tagged off Central America
that crossed the Gulf of Tehuantepec to central Mexico bring out the
TUNA TAGGING
321
possibility tliat in some years fish from Ccmtral Aincrira iiia\ iiioxe
into these fishing areas.
Recoveries at various localities of four j^ellowfin, tagged in February
within a few miles of each other near the Gulf of Tehuantepec, may
indicate that the schools into which they were released first entered the
Gulf of California around May, moved to the Baja California fishing
grounds by August and then traveled to the Revilla Gigedo Islands in
October and November (Figure 6a).
FIGURE 5b. Yellowfin tuna movements of 75 or more miles as shown by recoveries of fish
tagged in 1953 and 1958. Uncircled figures represent origins of the tagged fish.
CjOO
( Al.lFOKNIA FlSir AND GAME
FIGURE 5c. Yellowfin tuna movements of 75 or more miles as shown by recoveries of fish
tagged in 1953, 1956, and 1958. Uncircled figures represent origins of the tagged fish.
The Baja California fishery is exploited effectively by purse seiners
and baitboats during late spring, summer and fall and substantial ton-
nages are caught. When the fishery fails, generally by winter, the area
or areas to which these fish disseminate are in question. Since there
were no recoveries of Baja California tagged fish along the Mexican
coast it appears there was little or no movement in that direction. Tag
returns did indicate some dissemination of fish from Baja California
to the Gulf of California.
TUNA TAGGING
323
FIGURE 5d. Yellowfin tuna movements of 75 or more miles as shown by recoveries of fish
tagged in 1952 and 1955. Uncircled figures represent origins of the tagged fish.
324
CM, IFORXTA FISTT AXD OA:\rK
II /
-O
oo
- lO
00
O
o
O
o
-O
-lO
(7)
o
o
ID
o
TUNA TAGGING
325
'in
CM
•o
CM
1 1 1 1 1 1 r
•o
1 1
a
— '7~"~
"T""^ — f
UJ $
/
}
K -!:
H
/ /-
UJ o
2
/''■'N-/
</)
> ^ "^
UJ
/•* J^"^
K
w o i •
S
(*/ «
z o
UJ o z f^
UJ
)^<
0
UJ tiJ
5 ^ S -
> UJ o
>
"Si
•
O
OO
5 Q
O
. 2
(^ \___— .
o
00
r v\
> '
O Z Z 2 Z
O
i** J
O bJ
O 3 UJ o o
UJ
\n C^
5 Z
UJ -3 UJ cr
o u.
) y
z>
<
S % " - -
z Z o -
o
z
y \
z
UJ 2 - UJ " O
2
J
1- z
LEG
EASO
GEO
HAV
NEW
16*3
o
ii
fOin
/
0
z
to o >- \-
J < ,-
J
o
OO
il <=•
< < 1- <
< E
CE /
n
1
1 s
1- 5 < -J
z
H O
) 3 ^ J
/
w
<D
- ^
^ j
\ Z X
in
UJ
o /
oO
>
* i
>
i
[ ^ (^
o
o
A 1
o
L^>\V " /
e
\ /
•
o
\ J.
o
0>
0>
/
^UJ
0
in
e
31
\e)X
\ UJ
y
)
\
\
0
O
)
\
\
0
O
O
\
O
o
o
\
\
^
\
<<J
^
\
e
f
•
ID
O
/
lO
o
V^
\
'^^ _^
P
\
<2
\^
Z
\
o
(A
\
H
>-N
(T
Ot-
UJ
0
o
^-w.\
O
>»— ^^
a.
n
e
O
/ vl-
)
o —
"~
4 .;^
UJ
J
^-J<sy
«
> «
o
^^^bV
o
-^
0
<
-1
>
J 1 1 1 L_
UJ
K
tt-i ,_
• lO
• o
•lO "O
•lO
CM
CM
•~ —
o
c
a
3
■a
cs
•o
o
• — t/1
<D ^
> -o
1- CT)
O
>. ■*-
^ 0)
l-v
E
>
o
E
D
c
3
_o
"5
>-
SI
a:
O
326
CALIFORNIA FISH AND GAME
Substantial numbers of recoveries of fish tagged off Baja California
have been made the following season (Table 7), many within 90 miles
of the point of tagging. One tnna tagged in July 1956 Avas recaptured
842 days later only 87 miles from its release point. The small number
of off-season recoveries reflects their virtual disappearance during that
period of the year. This suggests the possibility that Baja California
tuna migrate to areas not subjected to fishing at that time of year.
TABLE 7
Season of Recapture for 167 Yellowfin Tuna Tagged, May to December, Off
Baja California, 1952-1958
Within-season (May to Dec.)
Off-season
(Jan. to Apr.)
Within-season
(One year later)
Within-season
(Two years later)
150
4
12
1
Fish tagged off the Gulf of Guayaquil and Peru did not move from
these areas into Central America (Figure 7a, b). Movement between
the Galapagos Islands and the Gulf of Guayaquil does take place as
evidenced by one recovery. Recoveries made along the coast of Peru
indicate that there is some movement between the Gulf of Guayaquil
and the 14-Fathom Bank throughout the year.
COCOS IS
MALPELO IS.
GALAPAGOS ISLANDS
\
COLOMBIA
YELLOWFIN TUNA MOVEMENTS
TAGGED IN MARCH -OCT-
LEGEND
WITHIN SEASON RECOVERIES
TAGGED IN MARCH
-- TAGGED IN SEPT.
TAGGED IN OCT
DIRECTION OF MOVEMENT
FIGURE Ta. Yellowfin tuna movements of 15 or more miles as stiown by recoveries of fish
tagged in 1954 and 1958. Uncircled figures represent origins of the tagged fish.
TUNA TAGGING
327
9
0'
8
5-
70
.
5-
COCOS IS.
=Y=
T
MALPELO IS
9
/ COLOMBIA
0"
(
-^ \
a
a
/
ECUADOR
GALAPAGOS
ISLANDS
^^ /| 1 GULF OF
^y YELLOWFIN TUNA MOVEMENTS
/ /|/ ,J TAGGED IN NOV - DEC.
S'
{ i '■'
LEGEND
WITHIN SEASON RECOVERIES
\ \\^ POST SEASON RECOVERIES
\ ' \V^ -i — DIRECTION OF MOVEMENT
.
\ ' \^
\ ^
-
\ -^
10-
\
SPOT
W \ "^
10*
^ 1 1
9
1 1 1
0'
1
8
5- a
1 \ T 1 1 — ; 1 :
3" 75*
70*
FiGURE 7b. Yellowfin tuna movements of 75 or more miles as shown by recoveries of fish
tagged in 1952 and 1958. Uncircled figures represent origins of the tagged fish.
Tao'g'ing mortality and nonobservation of tags during normal
liandling and processing of the tnnas have, without doubt, materially
affected the recovery rates. Even so recoveries of tagged yellowfin
tuna from 1954 to 1959 indicate a rate of harvest which in most areas
would not be expected to have an appreciable effect upon the popula-
tion (Table 8). Exceptions might be the Baja California and Peruvian
fisheries.
TABLE 8
Recovery Rates of Yellowfin Tuna Tagged in Ten Fishing Areas, May, 1 954 fo May, 1 959
Fishing area
No. tagged
No. recovered
Percent returned
Baja California
Revilla Gigedo Islands
Coast of Mexico
Central America
Clipperton Island - - -
1,845
421
2,321
2,412
54
76
330
51
1,078
70
150
7
8
6
0
0
1
0
48
0
8.1
1.7
0.3
0.2
0
Cocos Island
Galapagos Islands
Ecuador-Columbia
Guayaquil-Peru.. -_
0
0.3
0
4.5
ChUe
0
328
(■ \I,IK(IK'\1 A I'lSII A \I) (;A M I')
Sliiiii;iil;i :iii(l Scli.-id'cr (IDHf)) sliidicd llic rcl;il ioiisli i p liclwccii
|)()|)iil:il ion .•ihiiii(l;i lire .ind lisliiii^ iiitciisily in llic ciislci-ii l*;i('ili(' Tor
the ycni's II'MI lo ll'.').",. Tliry coiicliKlcd lli;M (isliiii!^' Ii;is liiid ;i fc;d
cd'ccl ii|t()ii llic stock (>r c;is|cni I'aciCic _yc|]o\vlhi liiiKi, l;ikcii in llie
tifjffjreji'Jil c, (i\('r llic pci'iod sliidicd.
l\;illicr l;ir^'c dinVrciiccs in rccoxcry rates exis1 hclwccii llic cciilcr
()!' the lisliiiiij: raiij^rc oil" Mexico, Cciilral ATnci'ica, l^^ciiador-Colotiihia
and areas near the iiorllicni and soiillicni cxlrcniies olT I'.aja Calil'ornia,
and Guayaciuil-Peru. Tag rc<M)vcrics Irom r>aja ( "aiirornia and I'crn-
120'
I I
no*
~i —
30
25
20
ADALUPE IS.
0
SKIPJACK MOVEMENTS
TAOOEO IN MAY
LEGEND
WITHIN SEASON RECOVERIES
OVEMENT
30
-25
20
REVILLA GIGEDO IS.
120*
-L 1 I i:
15*
I 1
no*
FIGURE 8a. Skipjack movements of 75 or more miles as shown by recoveries of fish tagged
in 1958. Uncircled figures represent origins of the tagged fish.
TUNA TAGGING 329
Guayaquil were 8.1 aud 4.5 percent respectively. Tagging in the cen-
tral areas of the fishery yielded between 0.2 and 0.8 percent.
The reasons for these differences, which are considerably more diver-
gent than would be expected, are not readily apparent.
Recoveries of Tagged Skipjack
Through Xovcmbci' v'.ii. lli.l!). 237 of 14,26o tagged skipjack bad been
received. They had been at liberty from one to 271 days and demon-
strated straight line movements of up to 720 miles. Those having
moved 75 or more miles were selected for graphic presentation (Fig-
ures 8, 9, and 10 j. Detailed information for every recovery can be
found in the Appendices.
Baja California and the Revilla Gigedo Islands movements (Figures
8a, 8b, 8e, 8d) were by fish that had been at liberty from 8 to 139
days and traveled 80 to 410 miles. Fish tagged in these areas in .M;i\-
'Figure 8a) geuprally mo\i'(i iifjr-ofi'^t. one goinir from Roca Partida.
Revilla Gigedo Islands, to liaja <'rilifornia. Thi>, nottlierly movement
was also demonstrated by some of tin- June tagging returns ('Figure
8b). Returns from July tagging C Figure 8c j demonstrated a predomi-
nant northerly movement, extending to the California-Mf^xir-o border:
however, one-third were recovered south of the tagging point. All
recoveries from September tagging showed a southerly movement
(Figure 8d).
<")nly three returns were received ffom tagging off Mexico and Cen-
tial America ('Figure 9), two of wliidi had moved more than 75 miles.
Both were recovered north of the point of tagging.
Movements shown in Figures 10a. b, and e for Ecuador and Peru
were from fish that had been at liberty from 16 to 192 days, and had
moved 75 to 120 milHs. April tagging returns from this area ('Figure
10a j demonstrated northerly movement from tin- 14-Fathom Bank to
the Gulf of Guayaquil and Ecuador. September and October tagging
Figure lObj showed an interchange of fish between the 14-Fathom
Bank and the Gulf of Guayaquil, with one fish moving from the Gulf
of Guayaquil to an area north of the Galapagos Islands. November,
December and January tagging returns ('Figure 10c) showed several
movements to the Gulf of Guayaquil from the 14-Fathorn Bank, and
one to the 14-Fathom Bank from tlK' (lulf of Guayaquil.
Discussion
Returns from tagging off Baja California indicate a northerly- move-
ment in May and June ("Figure 8a, b) ; a tran.sitional period with
movements both north and south during July (Figure 8c) and an
'■ntirely .southerly movement in September ("Figure 8d). Movement
between the Revilla Gigedo Islands and Baja California was evidenced
by a single recovery off Baja California.
Returns from tagging off Ecuador and Peru revealed a general inter-
change of fish between the 14-Fathom Bank and the Gulf of Guayaquil
(Figures 10b. c). Returns from tagging during April CFigure 10a)
demonstrated a movement from the 14-Fathom Bank to the Gulf of
Guayaquil.
A skipjack tagged in October near the Gulf of Guayaquil and re-
covered 45 days later north of the Galapagos I.slands indicated a move-
ment between' the mainland and the Galapagos Islands.
330
CALIFORNIA FISH AND GAME
FIGURE 8b. Skipjack movements of 75 or more miles as shown by recoveries of fish tagged
in 1953 and 1958. Uncircled figures represent origins of the tagged fish.
TUNA TAGGING
331
120°
30
25
20
GUADALUPE IS
30
20
V I
REVILLA GIGEDO IS,
I I
120°
115°
10°
FIGURE 8c. Skipjack movements of 75 or more miles as shown by recoveries of fish tagged
in 1953, 1956, and 1958. Uncircled figures represent origins of the tagged fish.
332
CALIFORNIA FISH AND GAME
K I
120°
110°
~i —
30
25
20
GUADALUPE IS.
PJACK MOVEMENTS
ED IN SEPTEMBER
30
20
REVILLA GIGEDO IS
120°
110°
FIGURE 8d. Skipjack movements of 75 or more miles as shown by recoveries of fish tagged
in 1955. Uncircled figures represent origins of the tagged fish.
TUNA TAGGING
333
oin 'O
M CM
■v 1 1 1 1 1 1 1 1 r-
•«
•o
•«
0
O
CO
0
(0
111
bJ 5
« > W
(- _, O 5
Si S ^
2 ^ K 6
^ ^ s
> ° 2
2 E w « u.
o < o
(J u
2£ Q _l w
u u z
< o o
? 1 IS
« -a
> 5
1 i
/
f'
r-^
•
o
(S
o
lO
00
<
/
n
a:
J
Ir-
< o
o
o
o
e
o
\
0
o
0>
/
,--/
Sr
0
in
/
e
in
0
o
o
o /
/
0
O
O
o /
-V
V. /
<C/
j
o
o
^
f
e
in
O
^
(Tl
o
o
/
<2
o
o
Z
o
q:
bJ
0
o
^
/ V J)
UJ
o
-I
o
^
^
0 <
_l
-J
>
bJ
CVJ C\J
"lO
•o
•lO
O)
o
c
-o
(U
cn
o
c
O
-C
[a.
cn
LU
O
4—17250
334
CA!.I7()KX1A FLSii AND GAME
GALAPAGOS ISLANDS
o
I ' '
COCOS IS.
c7
MALPELO IS
I . I ~T-
COLOMBIA
SKIPJACK MOVEMENTS
TAGGED IN APRIL
LEGEND
WITHIN SEASON RECOVERIES
DIRECTION OF MOVEMENT
III' ^1
FIGURE 10a. Skipjack movements of 75 or more miles as shown by recoveries of fish tagged
in 1959. Uncircled figures represent origins of the tagged fish.
COLOMBIA
SKIPJACK MOVEMENTS
TAGGED IN SEPT - OCT
LEGEND
WITHIN SEASON RECOVERIES
DIRECTION OF MOVEMENT
FIGURE 10b. Skipjack movements of 75 or more miles as shown by recoveries of fish tagged
in 1958. Uncircled figures represent origins of the tagged fish.
TUNA TAGGING
335
GALAPAGOS ISLANDS
MALPELO IS
COLOMBIA
SKIPJACK MOVEMENTS
TAGGED IN NOV. - DEC. - JAN.
LEGEND
WITHIN SEASON RECOVERIES
■• — DIRECTION OF MOVEMENT
FIGURE 10c. Skipjack movements of 75 or more miles as shown by recoveries of fish tagged
in 1957 and 1958. Uncircled figures represent origins of the tagged fish.
YELLOWFIN TUNA GROWTH
A second objective of oiir tagging program was to estimate the
growth of yellowfin tuna. Many fishermen removed the tags and sent
them in by mail. This prevented our obtaining complete recovery data
on all 263 tags returned to us. Regardless, we did get complete data
on 124 yellowfin tuna tagged off Baja California and the Revilla Gigedo
Islands, 14 tagged off Mexico and Central xVmerica, 19 tagged off Peru,
and 5 from other areas. These fish, 440 to 990 mm. fork length at time
of tagging were at liberty for one to 842 days. Detailed information of
individual tag recoveries is tabulated in Appendix B.
Baja California-Revilla Gigedo Island area data indicate that aver-
age one-year growth rates for similar sized yellowfin tuna were not the
same for each year of tagging. At time of tagging, size ranges of the
fish used for growth analyses were 440 to 650 mm. for 1953 tagging,
585 to 645 mm. for 1955, and 500 to 750 mm. for tagging during 1958
(Table 9). One-year growth rates were 200 mm., 420 mm., and 350
mm. for 1953, 1955 and 1958 respectiveh". Data from the remaining
areas of tagging are not sufficient for annual growth rate determina-
tion.
336
CALIFORNIA FISH AND GAME
o
•a
>-
5
o
■«
t4
-H OS r-
03 t-
CO lO i-H
■Hg
d oi ■*
c3 <a^
<N rl <N
>3
w.
<0 "O 05
m
lO >-H 03
CD
C3
-S -^
d -H d
m
Cl
_o
'm
0)
t-,
bO
£
© CO o
o
rt lO 00
+^
•* CO -^
**H
-f^
1 "O <N
o
fl
1 1 1
03
HH
1 1
O
*+3
CO
-tJ
c3
G
-t^
0)
CC
O O 05
Tf CO ^
|!«
CO rt in
CO CD CO
c
«
<o
k— 1
1^
t^ o t^
00 o t~
^X
^
odd
CM O lO
-t-3 ,
rf >1
-^J
03 u
a;
t^ >0 CO
c
to Ol CO
CO <M CM
IS
1 1 1
rt
^ ^ CO
C3
CO •* t^
d ic -i
CO -H rt
lO a: CD
^
■— i ^-s
-<J
bc ?:
0 "
QJ S
1-1'-'
a>
O "O o
bC
in tp no
coco Y
o >o o
Tf 00 o
Tt< LO "O
**-( en
°-3
is 3
J2 ^
UO ■* CO
? ^
^ r-H 00
^.s
■3^
Sm
S M
1953
1955
1958
TUNA TAGGING
337
Data used for growth analyses of yellowfiii tima of the Baja Cali-
fornia-Revilla Gigedo Island area were from recoveries, through No-
vember 30, 1959, of fish tagged during 1953, 1955 and 1958. They were
from fish that had been at liberty from one to 367 days (Table 9).
The change in length of each fish was plotted against days at liberty.
For each year, a straight line was fitted by least squares (Figure 11).
Regression analysis, using the method of Ostle (1954), of the growth
data was undertaken to determine if there was a significant difference
between the growth rates for 1953, 1955 and 1958. These tests showed a
significant difference {F =: 11.07; F oi ^^, loo) = 3.98) among the regres-
sions and further showed significant differences {F ■= 270.50 ; i<\„i (o, loo)
= 4.82) among their slopes. We conclude then that yellowfin tuna
tagged in the Baja California-Revilla Gigedo Island area during 1953,
1955 and 1958 did not exhibit similar growth characteristics, and should
therefore be treated separately.
400 f-
Y = -4 1605 + 0.5590X
Y=-53 5329 + I I489X
Y=-2I 8035 + 0 9586X
200
DAYS
250 300
AT LIBERTY
400
FIGURE 11. Yellowfin tuna growth for the Baja California-Revilla Gigedo Island Area during
the years 1953, 1955, and 1958.
338 CALIFORNIA FISH AXD GAME
Inspection of the growth curves reveals an apparent body length
shrinkage graphically illustrated where the growth lines intersect the
ordinate. Exact values for these intercepts are — 4.16 for 1953 taa'ging,
—53.53 for 1955, and —21.80 for 1958 (Table 9). The many varicibles
involved in measuring fish at sea and ashore and in body length shrink-
age brought about by freezing are the main causes of this apparent
negative increment. Loss in body length due to freezing has been
demonstrated bj' Godsil and Greenhood (1951). They found that 54
Hawaiian j^ellowfin tuna, averaging 615 mm. in body length, lost an
average 8.28 mm. when frozen for four to five weeks. This loss was
slightly less than determined in subsequent work by the authors.
Our one-year growth rates determined from 1955 and 1958 tagging,
in the Baja California-Revilla Gigedo Island area, are much the same
as noted by Moore (1951) from modal progression of length frequen-
cies of Haw^aiian tuna caught during 1948 and 1949 ; and by Schaefer
(1959) from temporal progression of size classes of Mexican yellowfin
tuna caught during 1955 and 1956.
Data from our 1953 tagging reveal much slower growth than for the
other two years investigated. This difference probably is valid, since
the data agree with modal progression of length frequencies from that
area.
SUMMARY
1. The California tuna industry is the most important fishery industry
in the State. Yellowfin tuna and skipjack compose a single fishery
extending from California to Chile. Because of the value of the
fishery to the economy of the State, the Department of Fish and
Game has gathered data pertinent to its management.
2. It was felt that tagging offered the most direct method of defining
the tuna stocks that support the eastern Pacific fishery. The first
successful tuna tag was developed in 1952 by investigations of the
California Department of Fish and Game. Wilson (1953) reported
on results of initial field trials. These trials demonstrated that
yellowfin tuna and skipjack would survive tagging, and the tags
would remain in place with no apparent effects on the fish.
3. Three vinylite tubing tags, Types E, F, and G, looped through the
flesh immediately behind the second dorsal fin were tested during
a field trial from October, 1952 to April, 1954. During this time,
4,204 yellowfin tuna and 2,839 skipjack were tagged. Based on re-
covery rates, the Type G tag was selected as the best.
4. With the marketing of an improved ink the protective outer jacket
of the Type G "spaghetti" tag was removed in 1956. An improved
yellow vinylite, Resinite X-270-I, was used in the construction of
all tags starting with 1957.
5. Dart tags were field tested against the Type G tag in 1959. Skip-
jack returns were in favor of the dart tag.
6. From 1952 through 1959, 13,213 yellowfin tuna and 14,265 skip-
jack were tagged in the eastern Pacific. Of these, 263 yellowfin and
237 skipjack were recovered.
TUNA TAGGING 339
7. Yellowfin tuna and skipjack recovered 75 or more miles from point
of tagging were used in demonstrating migrations by months of
the year.
8. Both yellowfin tuna and skipjack moved north along the coast of
Baja California during May, June, and July. By July some fish
had started to move south and southerly movements continued
through September and October.
9. There was an apparent inte^-change of yellowfin tuna between the
Revilla Gigedo Islands and Baja California. For skipjack, however,
the movement was one way — from the Revilla Gigedo Islands to
Baja California.
10. Tag returns indicated the fisheries off Baja California, the Gulf
of California and the Revilla Gigedo Islands are supported, in some
degree, by yellowfin tuna moving north along the Mexican coast
in winter and spring from at least as far south as the Gulf of
Tehuantepec, and probably from as far south as Central America.
This was not found to be true, however, for skipjack.
11. Yellowfin tuna and skipjack did not move between the Central
American fishery and those off Peru and the Galapagos Islands.
However, yellowfin tuna moved from the Galapagos Islands to
Peru and skipjack moved from Peru to the islands.
12. Yellowfin tuna and skipjack traveled betw^een the Gulf of Guay-
aquil and the 14-Fathom Bank.
13. The Baja California-Revilla Gigedo Island area data were sufficient
for annual growth rate estimation. Based on tagging, one-year
growth rates for j-ellowfin tuna 440 to 750 mm. body length were
200 mm., 420 mm. and 350 mm. for 1953, 1955 and 1958 respec-
tively.
ACKNOWLEDGMENTS
Investigations of this type require the whole hearted ('fToi-ts of ]iiaiiy
people. Mr. Robert C. Wilson instigated the program in 1952 and the
first tags were developed by Mr. Edward C. Greenhoocl and Mr. Harold
B. Clemens. Since that time the program has been under the direction
of a number of people and each contributed materially. The early
experimental work was conducted aboard the research vessel N. B.
SCOFIELD and sincere thanks are due Captain Ivo Kuselj and his
crew.
The lion's share of the actual tagging fell upon Pish and Game
Assistants who spent long and arduous hours at sea. Appreciation is
also extended to the skippers and fishermen of the tuna clippers who
were most co-operative in allowing us to accompany them to sea. Special
thanks are due Captain Lou Brito and the crew of the tuna clipper
SOUTHERN PACIFIC (now a purse seiner) who were especially co-
operative during six different tagging trips aboard their vessel.
We wish to acknowledge the advice and counsel given by Mr. Nor-
man Abramson in the statistical computations of the growth section.
Miss Judith Cohen drew the charts and figures and special thanks are
due her.
340 CALIFORNIA FISH AND GAME
LITERATURE CITED
Blunt. C. E.. Jr.
1954. Two mi(l-P;ifific recoveries of California-tagged alhacore. Calif. Fish and
(Jame, vol. 40, no. 3, p. 339.
Collyei'. Robert D.
1954. Tagging experiments on the yellowtail, Seriola doisalis (Gill). Calif. Fish
and Game, vol. 40, no. 3, pp. 295-312.
Ganssle, David, and Harold B. Clemens
1953. California-tagged alhacore recovered off Japan. Calif. Fish and Game, vol.
39, no. 4, p. 443.
Godsil, H. C, and E. C. Greenhood
1951. A comparison of the populations of yellowfin tuna, Neotlivnnus nuicrop-
tenm. from the eastern and central Pacific. Calif. Dept. Fish and Game,
Fish Bull. 82. 33 pp.
Lahr, Leslie E.. and others
1959. A field study of the relatire visibility of various colors. Calif. Fish and
Game, vol. 45, no. 3, pp. 203-215.
Moore. Harvey L.
1951. Estimation of age and growth of yellowfin tuna (NeofhuniiKS macrop-
tenis) in Hawaiian waters by size frequencies. U.S. Fi.sh and Wildl.
Serv., Fish Bull., vol. 52, no. 65, pp. 133-149.
Ostle, Bernard
1954. Statistics in research. Ames. Iowa State College Press, pp. 1.33-137.
Schaefer. Milner B.
1959. Report on the investigations of the Inter-American Tropical Tuna Com-
mission for the year 195S. Inter-Amer. Trop. Tuna C<jmm., Ann. Rept.
pp. 34-74.
Shimada, Bell M., and Milner B. Schaefer
1956. A study of changes in fishing effort, abundance, and yield for yellowfin and
skipjack tuna in the eastern tropical Pacific Ocean. Inter-Amer. Trop.
Tuna Comm., Bull., vol. 1, no. 7, pp. 351-421.
Wilson. Robert C.
1953. Tuna marking, a progress report. Calif. Fish and Game. vol. 39, no. 4,
pp. 429-442.
Yamashita, Daniel T., and Kenneth D. Waldron
1958. An all-plastic dait-tvpe fish tag. Calif. Fish and Game. vol. 44, no. 4,
pp. 311-317.
APPENDIX
342
CALIFORNIA FISH AND GAME
oo
ON
01
o
o>
>< E
Q 1
a. ^
Q- if
>>
0 *
a3P5mM«ffl«fflM
M CQ M ffl M M
MfflMMMMMMMQMtncBPSCO
K
P-ffflPQpLiP^pQPQPQPQ
Ph oq cl, cq D-i Ph
pHCQC-lDHPHfllPHPH&HSaO-lOHaiWffl
QJ
■« ^
-H00iMlNI>iOOf0O
' 1 00 "O ^ to
•*iO00O00OCIOOCD03iNlNO^
'OtvOOico-HC^roo
1 1 05 to 00 •*
r^io cococoi)<— iT)<oco o^ci
d
II
C05N-HIN rtC^^lM
. — 1
rt 0 ^OCI Ort rtrt
J
00
s s
p
-1^
-U
00 0 'H 10 «0 1 ' ^ IM
1 00 t~ 0 1 t>
OlOt-i 1 1 lOOCOCDtOtO POO
in 0 1 IN 1 1 1 -H M
I t-H ^H t— ( 1
OICO— 1 1 1 1^00 1^1 1 iClrH
§ P'
rt 1 ^ 1 1
1 1
i-H 1 0 ^ 1 1 l-H l-H
£ a
l-H
Tt<O'nTi<0200O'H02
^ 1 O-j — 1 IN CD
COOO>-ICOCOt^t^^COO!NTt<l^COt-
mincootNcoMOco
. CO Tfi rt CO
CDiO t>. ^CDTt* ^—1 OOOO
n _rj
C-) CS C-)
CO CO CO CO i-H C) •-I
>>
m t-
tH
>> a>
Jf J2
0
0="
0)
3
&:»»»»■
&:' ^' ^ ^
^ d ^ d ^' ^ d fs ^' ^ is ^" ^' ^' ^'
CO 0 t^ -^ CO fM 0: 'O C^l
TtH to CO to
C) Tl< 0 C) CD 00 00 00 CI -^ -f to CI C7i ^
't<-*<C0rt'^O'-HCJO
IN CO to -<
-t<C0COCO-t<— iCOtOto^ClCJOO'H
0
000000000
0000
ooooooooooooooo
hJ
0 — C-) 0 CO OI !M CO CI
^ Ol -H -H
^O^-^^CO'fO^CO^COCO'HCO
XI
3
z z z ^' :z: 2; z ^' iz
^i i^' 2; 2;
l^' 2; 2: 2; 2 2; 2 2 2 2 2; 2; 2^' 2 2:
*-+3
<NCOCOCOCOCOC^>OtO
Tj^ 00 CI 0;
CDCOOIO— iOO-^t0T^T)<iO0005^
C3
CO'-H'-i'OCO-^CO"^— '
0 -*< CO •#
CO'tC)CO-*<rt<OCOOTt<OCO^O^
fJ
0000
ooooooooooooooo
Ol CO lO fM i-O -f -f m -:t<
1 1 •* -* CO CO
CO^CJCDCOtOCD^COtO-^tOtOCOtO
IM (M IN IM (M C-1 IM W IM
1 1 IN O) IN CI
IN CI C) CI IN IN IN C4 C) CI C) CI 0 IN IN
,1 , ,
CO -< ^ -^ 0 '
1 1 , , , 1 , ,11
g 5
S
1 1 1 1 1 1 1 1 1
t- t^ t^ w t^ 1
1 I 1 1 1 1 1 1 1 1 1 1 1 1 1
.?^ s
t- 0
s= s
OJ *^
a)
3
oooooo>coo
to 0 0 0 0 to
000000 10 to OOiOOiOiOO
.^
-HCO-fOt^OiOOOO
<N CD CO to CO to
C4-t<CDOJr-icOa3003Tf<-t<OCO-H —
tOCD'OiO'O^iOiOO
to to to CD to to
to to to tP to to ^ to ^ -^ 10 CD t^ to to
C 5
0) c
H-1--
3
^ ^ ^ ^ p:' ^' ^' ^' ^'
■S ^ ^ id d >S
fg' is. >g' ^' &:' ^' ^ ^ is ^ ^' ^' ^' ^' ^'
C3
OQOOooocococo
10 to 00 00 to 0
^-H02-*t^OC0tOO-:t(C0C0C0OO
■^ CO »o to to 10 »o »0 'O
^ rt< Tt< Tt< Tt< Tt<
CIC^CI^CICO^CIOCOCICIO^O
0
000000000
000000
ooooooooooooooo
hJ
TfTfiCOCOCOCOtOtOtO
-^0000-1
rt^^CSCIOCOOCqCICOCOCOCOCO
ci!
a
a
3
g:z;^2;:2;2;2:;22;Z;
2; :z; 2; 2:^2;
222:22;22222222;2;2;
-*^
a
-4J
'30tOOOOO^-*<Tt<
(j-hOCOCOCOCOCMININ
00000^
CDCO'-iOOCIt^Tt^t^tO'-iCOCOCO^^
a
to 'l' ■* Tf ll< — I
INOINrt'fcOCOTf-^CICOCOCOCOTt*
i-J
ooooooooooooooo
ctft^t^OOOOO^DO
d IN IN IN IN CO
CJC^OCOCOCOClCOCOCItOtOtOCOCO
•g>iN C-) IM (N IN IN IN IN C^
IN (N 0 IN IN CI
C4CaClC)OC4CIINC10CIC|ININCI
PQ
-*-3
(-
CO to 00 00 00 0
1 1 C
1-H
>0 ^ ^ Tf
't
Tt"
to 00
03
-HrtlNIMlNININININ
iNINCJtOOJi-l— I—IININCIOINININ
Q
OJ OJ 0; Oj 0^ Oi
c a a a a a
^^•i?^^^^^'^-£?^'^^^i?
Sooooooooo
M 3 3 3 S 3 3
10 ^ ^-5 ^ ^ ►": ►^
333333333333333
o>
o>
»H
tH
TUNA TAGGING
343
ffl
ffl 03 ffl w
oa m « a<
03 03 M 03
Dh Pi Ch Dh
,« coa3P3mm
, pq CL( a< CQ m pQ
. tn Oh Cl,
cnooc^ooiooi>)t~c60it~ooooi03ioo
o CO oi 00
CO ^ 00 rt
•<^00»OiOiOiOCOCDCOiOiOOCO»0 00
00— <oooooO'Ot^ooioooi-OCTioooooo
o r- CI — I -H CO -t o
c<3 CO I r- t^ CO o C2
-I C)
'O 00 00 -^ CO
— < r~ " CI
I t^ 00
I lO CO
CO CO
1 00 o CI T)i r>. cc
I 'O "J< I t>. CO 00
' CO O: cc
I CO I^ t^
en ^
c] r^ o o en 'O X o o CI -H t^ t^ rH ^
-t<-Hooo^03t^ooocni-.t^oocit^
o CO c) CO
a> CO ■^
00
OOOcOCO^tOCOOON.OiCOCO^O'^
oocooot^cocDoaiOOJi^osooo-H
I « ^ I -. CO
Cl CO
t^ t>
00
CO
^" ^' tS ^' ^' ^' S:' ^' ^' ^' !S ES ^' '>$■ ''$. ^ is
^ t^ O 00 t^ ^ Cl 00 o t^ oi o »o CO o o o
CC'*'J<CO'*COCIC)COCOOCJCOCOCO'OC)
ooooooooooooooooo
00'H0000030000000'-0
> > ;
O CO 10 C)
-t lO CI -1<
'-<(NO'--iOiOT-ii— iioOiOCO'-hOcC
(N CO '!0 o en lO o ^ -^ O cj »o t^ lO en o lo r^
Tf COCOCOi-HCOCOOOCOCOCIClCO^C^CJCl
o ooooooooooooooooo
CO COCOCOCOCOCOCJCOCOCOCOCOCOCOCOCOCO
cq d C) o ct CI CI ca c) C4 CI C) ci ci ci ci ci ci
'^'^•z.'<z
O 00 CO 1<
O CI CO o
CO t^ to to
CI CI CI CI
Tt^00^'t^-t^^O■*-^■*— lO-^TftTj"
■^^Tj<Tf--fCICO'fC|-^CIC|-^-^--H
ooooooooooooooo
to CO to to to to to to to to lO 00 to to -^
CICICICICICICICICICICICICICICI
cnenoioi-Ht^t^ooooooototoio ooooootc
t^toCSOiOt^t^—t'^— '^— ^-^'-H^.-Ht-H COCOOOO
t^t^t^t^oot-t^ooooocooooocoooooooo oooot^oo
CICIOJCIdCIClCIClCIClCICIClCI
t^ 1^ t^ t^ t^ t~ t^ t- t- t^ t^ t^ 1^ t^ r»
to to O to O to to to O O to O to to O O to
00050:-HTt<Tt<Tl<0-H'-'— ■CICICOOJ—i^
lOtotoCOCCCDCOCOCDCOCOCOCOCOtocOCO
O to o o
O CI I^ ■*
to to to to
OtOOOOOOOOOOOOtOO
oo-HCiiotocococDcoooooooooai
to to to to to to to to to to to to to to to
o
CO
tSJg^tS^^^&r^^^pr^fg:^^^ ^^^i
to to ooooooooooooooo
dcJiOtotoOOOOOOOOOOOO
COCO—'i-HrHClCICICICICICICICICIClCl
^ -H CO CI
CO CO CO Tf
'. *^ rt ^ ^ ^ <.
COCOCOCOCOCOCOCOCOCOCOCOCOCOCO
OOOOOOOOOOOOOOO
bbobbobobbbbbbboo
CO CO to to to CI CI CI CI CI CI CI CI CI CI CI CI
ooooooooooooooooo
iCtOC0C0C0'*^Tt<^tt<'l''K-t^TjiTt<-f<
CICICICICICICICICICICICICICICICICI
2;2;^;Z
00 00 t^ CO
CO CO CI f
^ ^ '^ ^
CI CI CI CI
ooooooooooooobb
CI CI CI CI CI CI CI CI CI CI CI CI CI CI CI
ooooooooooooooo
COCOCOCOCOCOCOCOCOCOCOCOCOCOCO
CICICICICICICICICICICICICICICI
o
cq
in ^
cicqoocOTt<ioiococococococDcDt>.t^t^
CO
CO
■rf
,-H
CI
CI
CI
CO
>-
>.
>
(0
Vi
a>
CICICICICICICICICICICICICICICI
CICICICICICICICICICICICICICICI
>> >. >.
c3 53 rt
^ ->* f>i .>J
>1 >■, >,
rf s ri
C3 n 03
344
CALIFORNIA FISH AM) GAME
oo
C-M
0 en
C
. — na
c i
0 •—
u =
1 '•%
< =
X =-
Q =
LU <£
n no
!5 -^
Recovery
>>
is
^^PMpH^eL,pqii,caPHOHpapQPL,pa(xPHpqcL,meL,fL,p^«CL,cupL,CL,
Distance
traveled
(miles)
c
2 s
c
00Tt<t^00Ot~02C000lO lOCOC^ llCO3(MCO00-H 1 iiO03-*< 100
C«;t~0OTlH-:t<r.<.-ilN| 1 ICO lO it~iOr-H| 1 1 iiOlN^ 1
03 ^
csOLOO'^o-^cot^i^iO'-it^oosxrpcot^ 1000050500^05 i
t>00t^00t~Q0CO00-*<COt»-3<'*<00COCDI>.miM ilN-tt^CDt^t^OJ 1
CO
'3
o
1-1
^^^^^^^^^^^^^^ ^^^^^^^^^^^^
O lO C^J >— 1 O ^ CO <0 ■* O -— ' CO 'f '-' Ol O Ol O 'O OJ Tl^ 1— ' ^ ^ (M .-t
OOOOOOOOOOOOOO OOOOOOOOOOOO
COOICOCOCOCO-— 'C^l'— 'COCOCO-— 'CO coco-— ICO(NCOCOCCCOCOCOCO
h-l
•Z.'Z'ZZ'Z'Z'z'Z'Z'Z'Z'Z^'Z.^z, 'z:z,';z:ZZ^'Z,'Z'Z'Z'^Z
Ttl<MO-t<^-l<-H(M-lH-fl-flOTt<Tt ^^^rtC^)f,30p3^^iOTj<
OOOOOOOOOOOO O OOOOOOOOOOOO
iC lO CD 'O lO lO CO O CO lO lO O CO O 1 O »0 CO »0 lO lO 'O »0 »0 lO »0 lO 1
IN (M (M C^ C< (N (M C^4 04 <N O) C-1 IM (N ■ CM !N CS C^l CS (N IM C-l C-J IM (M (M i
Surface
temperature
(degrees
F.)
lNOq(M01<N(N(N(N(N<N(N<N<N^Tf':f<-*Tj<Tf<-*-*Tt<COCOCOCOCOCO
.— I— <.— (^H-H^H^-f-H^H^^-H.— (^H050505050505050505OOOOOO
j3 ^
Ml S
e 3
a; a
O O O O O O O O 1-0 O lO >.0 O lO O 'O O O >ra to lO >0 lO o o o o o
OOOIO)COCO^'OiOt-t^05iOTf<050^0)C<IO)C005'-<C>)-:t<iOaDO
OC0OCDC0OCDOOC0CDCDt>->0»0OOCDCDC0C0CC'Oi0i0»0»0U0
Longitude
^^^^^^^^^^^^^^^^^^^^te:^^^^^^^
cocococococococococococococococococococococococococococo
oooooooooooooooooooooooooooo
Latitude
:h;^:^Z;2;2;^;Z2;:z2;2;S:;:2;^^:z:2:;:2;^2;:z;:z;;z;:z^;^:z;
oooooooooooooooooooooooooooo
O) O) O) Ol CM O) Ol Ol CM IM O) CM O) Ol O) Ol C) O) O) O) C-4 C^I !N 0) C^l O) oa O)
OOOOOOOOOOOOOOOOOOOOOOOOOOOO
cocococococococococococococococococococococococococococo
CM CM CM CM C^l CM C-4 CM CM CM CM 04 CM C-1 O) O) CM CM C^I C^J 04 CI C^l CM CM CM CM CM
Q
1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
CMCMCMCMCM(NCM<NIMCMCMCMCMeOCOCOCOCOCOCOCOCOT)<Tt<Tf(TlHTj<.<i(
CMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCM
cJojcSoadoJcjcJoStSojcScaoSojaJoaSoScScaoSiSiSiScaojcS
TUNA TAGGING
345
,P^O^FLHp3PQnPL,(liPLinPL,fL,PL,|l|(l|PHPL,^PL,pH(lHCL<P-lPUFL,PL|(X,P^PL,PH(l4PL,
IM -H ^ rH r-^
O 00 IN O lO lO
Cl ■* to (N C^ IN
^ rt ^ CO
iCOOOOOcD^O'OOOOCDOO'Ot^OO
I ^C^C0C00?O'N00OC0C:t>-
i«5T(<<Nr^00IN 1^ iiCtOOSO
icceoosooiNo: ICC iwcct^'H
(N lO <N
■ c<3 1
1 ^ «5 1
1 to ^ (N IN 1
1 t^
r t^ (N
1 T)i to — 1
•O M*
1 (N 1
1 (N rH 1
1 CO i-H "O IN 1
1 1
1 •* t^
1 CO rt
■*
1
1
.— i
1
I'fOCOt^COt^-^COOO
I <N C^ w ■* -^ I I OO I
I O O 00 — I
I IN I CO
-— I (ID Oi Ci CO o
O to t^ tC CO CO
1 w CO 00 t^ «D 00
I Tf i-H t^ to IN 00
tDioiN'OCMooco-*ocooot^aiM<t^'Ht^to-*t^Tt<T)<
iO(Nt>-00tDtOl^lNiNr^tD'HrHlNtOt>.'H'-ir>.i-i<NlN
I I I I I I
h- O O lO 10 O
to to IN •-< r-. 01
I o o> t^ --I
I IN rt rH to
^^^^^^^^
^^^^^^
^^^^^^^^^^^^^
^^^?=^^
!S
^^^^
COl-HOCO^fffltO
oooooooo
'J'COINCO'-i-^COOl
(M O lO C' t^ o
Tf ^ CO '-' O CO
o o o o o o
>— ' 1— ' CC CO CO »0
COOOCllNOCOOlOCOtO^iO
Tj.O"'HrtrtiOiOINiOiNiCCO
ooooooooooooo
-HCOCOCOeOCOiNlNCOINCOiNO)
I^H^^t— I^H^Ht— I^H^^t— I^Hl— (^H.— (
Oi Cl ^ O -H T-H
O •— ' »0 ■^ >0 lO
o o o o o o
CO CO (M (M CI C^4
O
CO
lO lO o o
IN IN CO -H
o o o o
CO CO IN «»<
:z; 2; :z; :z; ;? :z; ^ 2; ^ Z ^ Iz; ^ ^ %%^'^%'z.'A'Z.%%%'^';?^ ^ ;?; ^ !2; ;z: ^z; :?; ;2;2;:z;^;
tO'OiC'OCOCO'O'l^
IN IN IN IN Csl Ol IN O)
O Ol to Tj< Tti o
lO 01 <— I -^ -^ IN
I CO CO to o »o 00
I Ol IN IN IN IN IN
^iO'*-^'*'*co-^tocoinooo
— iTt<CO^'*-*IN-*C001COi-'iO
i<NC101<NiN0)ININlNINiNlN!N
^ T}< to »0 '— 1 to
•^ ■* O O Ol o
to to o 00
CO C<3 O CO
o O 0 O 0 o
iO lO lO lO »o »o
O) IN IN IN IN IN
o
1 lO
1 (N
0 O 0 o
1 lO >o iC to
1 IN IN IN IN
eOf0C0C0b*l^00X00C0COC0COC0COCOC0COOiO5OsO5O5O5O5OiOlO5O>O5OiOiOlOlOiOiOiO>O5O>O>Oi^
OOOOOOOOOOafN'INtNCSj'NtNtNiNOOOOOOOOOOOOOOOOOOOOOOOOO
0'0 00'0 00»00000»0 00'CiOiOOOiOOOO'0 00»OiOOOOiOOOOOOOiOO>CO
OOt-*'-HOt^'— <C^CDO^*^-•C^■^■^"^'^OCOOlOlO'— 'C^C^CO"^"^"^OiOiOiOcD:£it^b»t-^XXC:0'— '
cocococooo^TfiTt<^^^^Tt<Tt<^it<Tfobbbooooooooooooooooogooo
onoooooooOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO
2H2H2H2HO^C^l2H2H2HSH2H2^?HS-^2H2HS-2H01C^01C^^lNlNINC^lNO^lNINlNC^INl^
^' ^' :^" z 2; ^' ^' ^" ;?; ^' z z ;2 2; :^' ^ ^ ^ z ^ 1^ ;?: z z iz; !2; z ^ 12; z z 2; ;z: iz: :? :?; ^ :?: ^: :?; ;? ^ ^2;
bbbbbroookiooooMoooooo«>ooooa)o^3^;u50'222^l22!22 — 2;2!2!212^
onoooOOOOOOOOOOOOOOOOOOOOOOOOOOOOOCOOOOOOOO
S,S-,MM^mS*2l<?fiS»<Sf<St'St<?t<St<?t<Sl<Sj<MMM«COCOCOCOCOCOCOCOCOCOCOCOCOCOCOCOC0COCOC0C0
wScSCSCSCsSoiSSSS^^^f^^oJoilNtNINOllNININlNINlNINlNINlNINININlNOllNlNINCSIN
^^^^c^NSSSrororoMSwMTOOTcoScocococococoeceococococococooocorococococococo
O3a!c8ci3c3sjcscao3ciiciieio3c3o3c4ciicac3ci3caij3:3c3oso3^oj^^^^^^^^^^^^^^^
5—17250
346
CALIFORNIA PISH AND GAME
oo
(VI
0£
C
.— ru
c
o
u
< =
>< >-
Q.
rn
<VJ
>,
s
>
o
° s
M 03 CO M
CL, Oh Ph CL,
Ph Ph a, PL< fii a< CM Ph pL, , Ph p, &, &< pq Ph Ph pp Ph cq
Distance
traveled
(miles)
O O T)< lO
CO CO 05 lO
OOiOO-fOOcO-HCOO iiOOiO iOO^OOOCOtH
t^C0C0 01OC0t^'^l> iT}<o-^ i^iO-^'O-^tO
4^
c
t—t
r^ 1 CO t>
CO 1 rt ,-1
1 1
»0 1 .-1 CO tN rH 1 lO »0 1 1 t>- 1 O 1^ t^ t CO ' '
' 1 i ' 1 1 '
Tt< r^ t^ !N
O t>. i-H C-I
1
CO
coioojoiocoocoo •*'co3i ojocoooo;
.-H CO — 1 Ol ^ 0) -H £0 1 CO CO CO 1 — 1 O e Ol CO CO
1 1 1 1
O i!0
^ CO
c
o
i-I
^^^^
^^^^^^^^^ ^^^ ^is^^^^
C32 IM (N t~
O ^ ■* IM
o o o o
CO CO iM CO
lOcncDOi-Hcnt^^o oc-io (Nc^iococ^io
COOr-irtlOOOlO^ r-^r-lr-H Tj<rt.-H(NrtTj(
ooooooooo ooo oooooo
CSC0 0.1C0<MCOC0O)C0 COCOCO — IC0C0COCOC-)
0)
XI
3
2:2;^^
Z'Z.'ZZZ'iz.Z'Z'Z, 222 222222
25° 44
25° 44
25° 10
25° 58
■-O'*lTt<C0(NTl<Tj<<NTt TtllO'J* inT}<T}(C0M<O
oooonoooo ooo oooooo
(N(N(NlMiMOq(MC^(N 1<NC<ICS 1(M(MIN(N(NIM
cii
Surface
temperature
(degrees
F.)
■a: cr. 'Oi c-
coc7oocooocooooooot^t^t^t^(^i>i^f~t^r~t^
o o o o
i> t- t^ t>
OOOOOOf^(^t^-t<'tTt<-:t<Tti-f<00000
t^t^I>t^t^t^cococot^r^t^t^t>I>l>t^l>t~l:^
^5
o o o o
— ■ ^ Ol ^
i^ t^ t^ r^
oiooooooioiooommoooioooo
(NCOt^OOOl^C^O'MO'OCOCOOiO^'Ot^T-ioS
COC0COC0C0t^»O»Ot^COCOCOC0CDt>»O>OiOC0C0
a)
T3
3
g
^^^^
^^^^^^^^p:^^^^^^^^^^^
SSS8
o o o o
Oi C^ -M '>J
OOOOOOtOtOiOCOCOCOCOOOi?Ot^t^tOiOtO
OOOOOOcOCOCOC^CS'N'NC^fMtOiO-^-^TlH
00O0'"00O00OO00OO00O0
-M C^l Ol Ol C^ C^I C-) fM CI -— 1 T— 1 ^ ^ i-H 1-H (M 01 (>) i^J (N
3
03
2;Z2;;2;
22222222222222222222
iO lO »o o
Tf rt* -^ Tt<
o o o o
CO CO CO CO
(N C^ iM IN
iOtO»OiO'OtOi-H'-HrHiO'OtOtO»0»0'M(NCOO«3
'^Tp•^TJ^■^■^t^T}^TJ^TtlOlOlOtOtOlOlOtOOOO
oooooooooooooooooooo
COCOCOCOCOCO-'^^rt^COCOirOCOCCCO'^'^tOtOtO
0)
oi
p
May 31
May 31
May 31
May 31
1 1 1 I t it^t^i>oooooooocoooaiojaiaiai
TUNA TAGGING
347
CC 03 CC OJ (/J ra M
PM Ph fL, PL, CL, m (i,
CO
Ph
M3 CO
PM PL,
lo in o CO o (N lo
CO
CD O
CD CD
PQ PQ ff) ,72
PQPQH Ph
CO a; C
ChPup;
aco
P5PL,
o o o 00
O lO
CO CO
T)< 00 CO
O! — 1 1^
Ol CO rt
C>4 CD
"O(N(NOOC0<NTj<(Mt~.00
t^OcocD-^corocoooocs
(M O CD I ^ lO
I C) f. i CD — I
m r ^ i-H CD I O CO
o I CD \ < r*
>n IN '
I (N
I IN
lO O
lO^— 'OCOt^Oi^OOt^CO
CO^OlCOCD'-'OOl — coco
rt^— I — ITl<r-< — — CM
00 00 CO 00 CO —1 -*
in
03 O)
CO
■*
CO CD
CO
IN IN
h» CO CO CD
't 00 CM CO
m oi CD
t^ o o
o
o
— o
C: CD
^s:^s:^^^^^^^ ^^^^^^^
"i "i ^ "i
fe <'^
>fe
c;cD'00OOoj-i<Tt<o— lO — ^t^— it~i^o
o >n CO CO CO lO r-H tt o in o in lo o 'O o o 'O
CO -i^ CO in in in in in »n o -+^ c^i oj co o^ co co o^
CO CD C-. C2
o) m c CO
3". cr. o
Ol Ol IM
o 00
CO — ■
O 0 o o
— O O) -H
o o o
0-. cr. -•
c o —
o o
CD m
o o
^ !z; IZ S; ^ :z IZ ^; !z :z; 12 'z, 'Z Z Z Z Z 'l^^
^CD — OOOOOOt^OOO
■*C0Or0C0 0IC0CMC0 04C0
ooooooooooo
ini^OOOt^OOt^OOt^OlcD
INCMIN<N<NIN<N(NlNi-lC^
^^
_< rt -t< — 1 -f -f Ol
Ol (M 'f IN 't* -f r-.
CO
lO
-f o
m Ol
O O 0 0 0 0 O
in in in in in in in
CM IN IN IN IN CM IN
o
CO
CM
o o
00 en
55!z;^;2;
^2::z:
^iz;
^ ^ ^ ^
^ ^ ^
•^ ^
in '^^ o in
m in o CO
CD CD t^
in m Ti<
00 cn
O CM
o o o o
CO 00 35 CO
CI ^ — • CM
0 o o
01 Ol •-'
CM CM CM
o o
CM 02
CM CM 00 00 00 CD 00
CO CO CO CO CO CO' CD O CO CO 1^
in ira 00 00 00 00 t^
t^ t^ i^ t- t^ i~ t^
t^ t~ -H (D
<35 05 O CD
(^ 1^ 00 t^
o o o o m o o o o o in
T-H ^H ^H CO -t in in CD t^ in Ol
in in in in in in in in in in in
o o o o o m
00 m CD o 00 -H
Tji in in in in in
c
o c
o
in in o o
1 1 o
2S 9S
OO
^o 3;
Ol
Ol CO CO o
1 1 t^
00 w
in
o; C-.
X
CO r~ in CD
T)<
in CO
^>'
'■^
^
£5
^
^>'
^>'
^
en en
en
en
en
en
en a>
en 00
— CM
en
cj 04 h- r- t^ Oi r--
o o o o o o o
o o o o o o o
CO CO CO CC CO CC CO
t^ i^ en Ol
m m o f
m m o;
in m -H
o o
CO CO
O 0 0 o
O O Ol -t
O 0 o
in in 00
o o o
o o
O CD
o o
C-
2; ^; 2; 2; Z 12: ^ ^; 2: 12 Z
rtrt— lrt,^rt.-l^,-HtOCO
OOOOOOOOO'J'.-H
COCOCOCDCOCOCDCOCOCDCD
CM Ol O) Ol CM CM CM Ol Ol CM CM
^:z;;2^^^^
&?;■
^Z
CO CO "^ '^ '^ "^ X
tP -rt^ Tt< "^ 'f -^ CO
crt Ol
CO b
-f o
0 0 0 o o o o
»0 »0 »0 »-0 i-O ».o o
<N CS (M csi c^a iM CI
3&
o o
00 0-.
^^J^IZS^
0 (Noi
20' N
20' N
07' N
S':Z
Ol Ol o -^
in in o Ol
CO CD
m in
O 0 O 0
M 00 o; 00
■ .H 3 O 0
X 0-. CJ-. -•
4) — « Ol
0 o
01 CM
(Xl
>i >* >. >.
»-? -^ "^ >^ ►
rt rt CM CM Ol CM CO
til M bi M M ti bj
US -:
« CM
CO •"■
CO -ii
I 00
IS '
>> >1 >> >>
^ cj ^ ^
00 *^ i^ *^ *^
eq — ^ ^H I— I
\a A A r^
QQ
348
CALIFORNIA PISH AND GAME
oo
to
Ol
o
to
3 *
a>
0£
-D
t^
TO
C
C
3
o
1—
u
c
< ^
a.
<
rv4
>
o
o
a;
* T3
.2 ?3 H
i S
^ S
X
T.
=: a X 33
S B &< ffl
cQ oa
CC 33
33
03
d, 33
33
33
o
1^
0)
M >0 O CO
>0 CJ 00 3-.
00 o o; t^
lO o
— ■ CO
CO
S
C-l CO
1 C7:
'X; oo
• O
M -H
i>\
o
00
3
0)
^^^^
^^
to
o
O
O -Xi 00 -H
- LO
^ ^
^^ CO CI »-0
cn -^
O lO
"o
rH C^)
C-4 "M O O
0 Ol
o 0
■M O
o o
.-- ^-- i-H i-H
O! ^
00 00
o
zz^z
O (M C^ CD
O CO -1< -H
C3:i Tf lO 32
^ c>4 cq "
^Z
O -H
CO CO
o
00
00 00
O O 00 00
00 00
00 00
^ 5
1-1 ^
-a
O
Q
o
^^^
iSiS:
^^
3
o
•^
Is'
•^z
-tJ
^
o ~
+3
O O
^
lU o
s^
a ~
3 M
H -I
t~ t^ 00 00
^ T^ ^ ^
o o o o
tJ* ^ Tt* Tt^
^:z: gzz
S i-( s
^ m CO
(-1 o o
o 00
O
V
lO — : lO ".
Oi Oi O O
-H .-I (M (N
.O XJ -D ^
lo » a> 0) 0)
US hN fen [i< P^
CD '
CJ
<N ^
O
■* "3! J7
lo ^ <;
C<1
d
IS ^
IS ►-:
CO ■^^ c-i
CO 00 CB O
t^ CD
03 'f
lO
CO O)
CD
t^ t^ O CO
c^ in
r- O
OI
-- o
^H
O) -H -H (M
'-I
^H
^H
—
^^ -s
o o
2:2
iC CO
•^ o
o o
00 00
^z
00 00
03 03
b- "^ ■3
lO -4 rf
00
o
o in o o
O O
o o
o
9 9
o
t^
o 'Cr. o ^
t^ -J
O CO
(^
00 00
•^
in
CD' CD t^ t^
i^ 00
CD CO
in
t~ t>-
t~
^^ ^
in
O)
O
CO
8§§8
CO o
ss
CO
Ol O)
o
CD
O
o
O
o
O 0 o o
00 00 00 00
Oi ^ Oi Oi
o o
00 05
0 o
00 00
o
03 ro
o
00
00
00 00 ;:;
a
TUNA TAGGING
349
PQO,
t/3 M
PhAh
ro rn rn r^[ ro ro
Ipapa e ffl pq pq
« pq .
cQpq 1
Oh
O
pq
o
o o
00 00
1 CD T»< O O "O O
O O 1
IN 1
CO
O
S
pq O o-j pq 02 C pq PC EC o X
pqH&.pqpqpqpqpq2;ccp^
OOOC^'^OOOOtDlNiN
lNTf<i-Hr-<m>00'C'*OT
o
CI iM
o
CO rH
•— 1
CO
I -H o ■* O CI 00
I IN .-H
o
CI CO
■o o
1 CO rf (^ 1
. CO
CO
1^ CO
0) lO
1 CO ^ C-) 1
1 IN
'-'
CO
•—I
OicoooiTtiicococO'-ir^
i-HOS.-lr-l-^O't'H'^CDO:
-^ -1 I rt IN —
I CI
o •-■
00
^
^>'
^>'
^^>»»'
^>'
^
c) 00
lO o
Tt< CO
So ^ b b b b
O O '-I '-I O -H
^ b
CJ rt
00
o o
o; r-l
t^ 00
o o
O O 0 O 0 o
1 f— 1 .— 1 T— 1 ^H ^H .— 1
i 00 00 00 00 00 00
0 o
00 W
^ ^
O "C
rt o
:5:?:e:|s:;
00 lO 03 — I rt CI o 00 1.0 C) —
OTfOOOOOiOiOO-*
oooooooooooooooot^oooo
;?;
»
VJ
ai
72
rji m m cc in m
M C/5
rrj
ai
«2
■c
■o
to
o
O
CTj
r^
o
o
o
o
CO
o
o
o
(^
o
o
o
CO
C)
CO
CO
CO
CO
CO
CO
CO
CO
-^
o
0
0
o
o
1 o
o
o
o
o
o
0
1
o
o
OS
■*
CO
1^
1 CO
CO
CO
CO
C)
CO
CO
CO
CO
CO
CO
I-H
o o
OO
o
O
o o
o o
o o
o
o
o
'O
00
CO
t^
t^
1
1
1 ,
,
,
,
,
,
CI
CI
CI
o
CO
CO
00
t^
t^
1
1
1 1
1
1
1
1
1
t-
1^
r^
t^
I^
r-
rii m mm m m m in m m m
'fOCOtOCOClOCO-^OiO
IN CO O CI CI CO 'J" CO O 'O t
COCO-^COCOCOCOCIOiCOCO
ooooooooooo
ClCOCOCOCOt^t^l^f-P
t^'»t'^*^"^'-l^^^^ I
CD t^ t~ 1^ t^ I^ t^ t^ t~ I- 1
00
^ o
■*
o ^
CO
CD CD
lo lo o o m o >o o o
0;01t»0>OCDCDl^OO
TJH 10 CD 'O lO "O >0 »0 'O
O O lO "O
CI O: t~ O
CO «0 "O iC
O O >0 IC O O »0 »0 »0 lO o
CI 00 o CI ".o CO o CO 05 i^ CI
iOTf»0'0»0»0>0>OTfiO>0
CO
o
CD CO
1(3 lO
o o
00 00
^^ ^^^^^^^^p:
IN IN CI CI CI C4 CI CI O
rHrt^OOOOOO
oooooooooooooooooo
^?:^
fS
^
^
b b b
CI
o
b
b
o o o
00 00 00
o
00
o
00
o
00
iSlSiSp:
00 CI CI CI CI 00 CD CD CI CI ^
0.-I— 1«— •COCOCO't-tO
0000000000000000000000
E
gSo
0.
Guayaqu
03° 35
03° 35
aimmmmxnmmm
OOOCOCOCOCOCO'.O
cococo'-i^t-i—i'-iio
cococococococococo
ooooooooo
vimm
m
m
m
o o o
CO CO CO
00
CI
o
CO
o
CO
o o o
CO CO CO
o o o
o
CI
o
o
CO
o
o
CO
o
mmmmaimmuimmm
■^-t'f'^'tO'^'fOOCO
CICICICICI^^^^^^
C0C0C0COC0-tf-*-*<-1'C0
ooooooooooo
IS fX|
QQ
Sooooooooo
NCICICICaCliNCICl
GOO
00
C)
lO i<
INCOCOCOCOaOlfflOO'-i
«— lrt,-irtrtrt,-iCliNCO
*^ *J 4^ +i
+J +^ +^ +J
Q
00 X.
ocjoc;ooc^o
OOOOOOOOO
O'
v.o
CALIFORNIA FISPT AND nA:\IE
oo
0)
C
o
u
< ^
X >-
5 -^
LU a.
a. „
a. 3
Recovery
>>
H
H
Pi
OOCQ
fflffipq
CQCQ
a
Distance
traveled
(miles)
O lO !N
IN lO
CO
^ CO
c
OOOOOOC^lO^OOC^lO-f-r 1
CO CO
+3
s S
a
1— (
1 1 Tt<
r 1 (N
CO o
'
^ C^ O ' ' >0 1 1 »0 1 t 1 IN CO LO 1
^ , , 1 , , 1 , , ,co- 1 ,
-f CO ^
-r o -r
1
00
CO CO
^ -o
O CO m LO LO CO CO •* -O O 33 CO -.o i '.3 o
CM -^ ^ O) ^ i -H CO
'3
13
0
iJ
is' ^' ^'
-* o o
o .-H .c
o o o
rt rf 03
X 00 t^
^>'
O -f
c o
o o
00 00
»o
o
p: ^ ^ ^ ^ ^ ^ ^ !S S: ^ ^ ^ ^ ^
lO LO LO LO »0 »0 LO »0 lO LO to lO LO •— < •— *
ooooooooooooooo
OiCJiOiOiCnO-. 33 03O-. 03 03003-^— ' 1
t^t^t~t-t>t>t^t^t^t^t>.t^i^oooo 1
3
c3
►-1
03° 41' S.
04° 03' S.
09° 04' S.
O 03
'J* CI
o o
CO CO
O O
m
CO
c
o
o
m m m m Ti rnin m Ti vi m VI v^ in rji
■O to LO lO lO lO lO lO -t LO LO lO lO C-) Ol
OOOOOOOOOOOOOCOCO
ooooooooooooooo 1
O3c:;'33c:3O3Cj3C3a332 33(3;o3a3C0co i
ooooooooooooooo
'a;
Surface
temperature
(degrees
F.)
00 00 00
IN CJ <N
f^ t^ r^
to 00
o
o
C^lCMC-)'NC^CqiNCMC<lClCMCM'NINe^lC>)
'O -^^ -.3 '3 '3: -3 '3 C3 '3 -3 'C^ '-Z 'C ^ '3 O
C 3
d) 3
O O lO
■^ 00 c-i
O LO o
82
CO 'O
i
O >0 O O 'O 13 O O O O LO O O LO LO lO
Or^CXOiOiOiO'-i^tNiNCOCOCO-^tO
»0L0t0»0»0t0c3C3C3CDC0OCDC0CDC3
-a
3
'3
a
o
81° 04' W.
81° 04' W.
81° 04' W.
b N
O -H
O 0
00 00
LO
o
Oi
^' &; ^' ^' ^' ^' ^' ^' ^' ^' ^' ^" ^' ^* ^' ^'
»OiCL0L0iCiO»O»Oi0tOiOiOtOt3»OtO
oooooooooooooooo
33C-. 3:03C3Cn3>03Cn03030303C-. C3C3:
3
03° 41' S.
03° 41' S.
03° 41' S.
oi CO
^ CO
o o
CO CO
o o
is
a,
m m m m m m m m m m m m m m oi in
13 LO LO LO LO LO LO LO lO lO lo lO lO lO LO LO
OOOOOOOOOOOOOOOO
oooooooooooooooo
O^. :ji Oi ^ Oi Oi O'. O"' ^ Oi ^ '^J '^ O'^ O'^ '^
OOOOOOOOOOOOOOOO
S
Q
Nov. 9
Nov. 9
Nov. 9
O CO
>' >
O 0
IN
So
i0L0i0»0OL0i0l3»3»0L0t0i0i0*0i3
„000000000 3 330000
TUNA TAGGING
351
a
■^
""^
'"^
"~"
o
0
^
0
5
5C
I— t
o
(N
M
lO
1
10
1— 1
05
0
_,
Ol
■*
■M
t^
^
S:'
':S
^'
^
^
.^
^
.;^
t^
— <
!N
o
CC'
'—
^
o
0
0
0
(N
0
Oi
0:
00
03
Sf
'Z
X*
CO
^
^
.^
^
o
0
Tt^
»c
•-t"
c^
(N
o
0
0
0
0
CO
0
O
o
QC
^
.^
,
t"-
t>
00
1
iC
«o
Lt
0
00
c^
^
0
iC
IC
iC
»o
^'
^
^"
K^
V
^
^
^
c
t^
w
^-
c
cc
0
-^
o
0
0
0
M
C5
02
s
a:
(Q
•a
a
m
M •
-'2;
;z
:^
^
to
S)«>
CC
1,1
^^
rt =^
'— '
.— 1
l— '
B.D
0
0
0
ca —1
0
(M
■30
0
0
0
0
-t
00
CO
'"'
(M
>
J3
I-.*
■4^
10 1^
s
eg
CO =;
P5~
lil
fcE-5'
352
CALIFORNIA FISH AND GAME
>1
§1
mzr^^^^ — ^^mmv2mtQm<nmmmuim
m rt
2^
ci,a,p3PHmpa«ffl^PH2HPLHCQCL,!i,eL,cuc-,PL,eL,
pan
ance
eled
les)
N crtCO'OWOO'OO'O— ifiNt^O lOriOO
00 •*
05 it-*C^'^C^OX'^ lOt^^iOC^ rc^ ^
00 3>
rt C<1
*= > -2
.2 S E
Qi-
OO 1 1 it~-*t^-*>0T)'O it^000h-t005 i05
1 CO
-H ,_-^
<N 1 1 iTj<o:ooo50ooco iiocO"*'-*>no) im
1 M
r^ TS ^
lO -^rt^Tj^Tj^-^j^Tj^iO iCiOiOiOiOiO lO
lO
X tj; s
^1-^
,|j>
(Nso-^iNroroTiiooMco— lO^ — c^— iiM'-i'-<ai
^ t^
d >.
■*|rtrt,-irfrt CCC^lCCC^ (N C<3
t^ t^
+j
I— 1
►>!
m u
Lh
i^
>. «
o
OJ
C3 J
>
o
Q-
i-H
a)
o
*i—
JC
gj
o
-4^
^' ^»»»»»»' ^»>"
^>'
t—
bD
-*< 00C^Tt<(MC0Tt<C<l(NOCCiOTOm lOiCCOO
t^ Ol
\—
c
!M OOOOOL-iOiOiOlMiOTjirt -HIMC^CO
'f CO
o
o ooooooooooooo oooo
o o
J
—1 (NC^COCOCC'N-^-HC^'MTf'NCO COCOCOCsl
O O
O
•— 1 |,-H<— (^^^^^Hf— li-H^Mi— <.— iF-^^Hi-H 1.— i^^^^<— 1
^H ^^
—
^3
a>
3
"S
Of
u
CO
Ol
3
iz; ^i z z :2' 15 ;5 !z: 12 !^ 12 Z Z 'z "z 'z, Z Z
15 :z:
X
00 OLO^OJOO^OL-OaiCOOt^ t~ioIoco
to Ol
03
Tf ^rtTt<iMOCqOOO)OOTj'CO COMMCO
CO CO
.^
J
a
tj
o ooooooooooooo oooo
O 0
fD
CC 'C^CCCC00CO(NC000iCTt^t^-^iO iiOiOiOiO
CO CO
z
'S
(N I(M(MINIMC^(NC^!N(NC<I!M(NIN IC^OIIMIN
Ol O)
UJ
1^
Q.
Q.
<
1/-I
1 —
no
Surface
Iiperature
[degrees
F.)
CO Ol
o
t^t~t^t^t»t~t~t^ t^l^l^t^t~t>t^t^t~l^t~
t- 00
^
lo o lo o "O o o o o in o lo lo 1-0 o o >n o o lo
o o
>"
rj '^
-HO)O5.^Tl<o;00O2CC00C-lMllD'-iTt<Tf<iO«-3<-*
-)< ^
0)
2 M H
iC lO -^ lO -^ -t -t -t -t* -t »0 »0 O »C L'; »0 to O LO lO
LO LO
^
o
s g s
a>
— ^-^
Of
^3
ro
s
ro
5
^' ^' ^' ^* ^' ^' ^' ^' ^" ^' ^' ^' ^' ^' ^' ^' ^' ^' ^' ^'
^>"
W
-*^
^ V
Of
tiD
MC0330000J'MOi-0"niO'H<NiNiMWCCC>3C^
LO O
fl
OOiO-HOOiCiOOiO'OiO'-iMMCCfOOJC^C-)
Ol o
O
oooooooooooooooooooo
o o
^
§
_©
"«
rt
hJ
(Noi— ic^roeo-^-Hc^rfrfrtcococoMMcocoM
CO Ol
m
3
fl
'z^'z'z^'zl^'z'zlz'zlz'z'z'z'zll^'z'z'z^
\z.z
■kj
S3 ^ ^^^^^^
'+J
•ZjiOOOt^t^OOl^t^iOOOOCOCCOCCCCOi-OLOiO
j2^MrocOOO'M(N'}'000'*(M<NCS(NCOCCCO
o o
o3
►4
CO Ol
oooooooooooooooooooo
0 o
cao)(N(MMroeoco«cococccocc>oioi-'5iO'Oinin
lO ■*
•JJC<ICS1N(N(N<N<N(NC^1<N<N(NC^<M(N<N(M(N<NIM
Ol Ol
pq
'-'' 1
icccot^t^^'-''-^'-^cc»o»o»n»ot^t^t^
Ol CO
:3
'=^<N(NO-H'-H— I-^!N'MC>)!N(M'MC^C^C^IMC<1C^
Q
n 33'3'33'333'333'd333'53333
0>
a a
10 01 <u
IS 02 C»
'
w
1H
TUNA TAGGING
353
ccpqpq ffl C3pq
Ph n P3 n n n
m(i,eMPL,mmeL,fflpqcL,cQ
,PHmpQpqpLip,ci<papL,sQpL,pm35(i,cQ
pq W 03 P3 W M
P3 n plh n PQ ixi
>o I IN t^ a> oi
00 I -* -* CO CO
io>oeoO'*OcDOOOin
rf<QOOI^C^O)OOCO>OINO!
I "O ■* 00 iC >o lO
I CO CO O ■* CO CO
I O 00 tc o o :d o
CO O CO CO CO CO --I
^ ^ r-i CO CO ^ CO
'O "O O 00 lO ■^
O CO -H (N !C ■*
rH ^ <N --I
CO 1
1 kC 03 to
t^ 1
1 00 •* lO
■^
rj< lO Tjt
I h- CO
O «D
I lO >o
1 lO tP
iCOIM00«00O)>OiOTf
icDOt^'Ht^r-t^cooo
to CC >0 »C »0 to »0 CO »o
CO 05 i
1 CO
00 10 1
' a>
to to
to
O I to to to o
IN I CS IN ■^ <M
C.|00<N"*i00tO00OrtCD05
cor-csc-ic-itOi-icocotDco
I I I
CO i-H 00
r^ IN iM
to to to (N r» t~
^ to lO to to to
I I
IN CO
to to
to 00 ■-< 00 t^ oi 05
CO to t- t- 00 00 CO
CO 05 O O to M
to to to to to
^ ^^^^ ^[SfStS'^^^CS^^tS fS^tS^tS^ ^^pStS^^^ ^^fSfS^^
to
CO
to o to to
IN O <N ^
IN CI CO (N
■<l<OtOdlNO'-iCOOOl^
■^^■>}<rtCOi-itO-«l<"tOtO
^COiNCO-^COlNi-HCOCOIN
to C) .-H O Ol o
IN .-H to (N O — I
CO CO CI CO CO CO
OJ— lOtotOOto — (CROtO-H'
Oto^COCOt-iCO tOO'HOtOi
COClCOtOtOCOtO CICO-^CONCI
to to o to 00
to rt d CO -^
o o o o o
■»f I Tf f^ to Tj^
IN I O IN O O
'^■ZZ'Z^z.Z'Z'Z'Z.'ZZ
Oiftor^oo^ooooTtfrH
■*'*tOiO'J<'l>.-H'*0-flN
COtO^tOCOtOtOCOtOtOtO
CI !N C) IN (N CI <N C) (N IN (N
'iz.'ZZZ'^.'Z :2:z;;z;ZZZZ :^ :z; :z; 2; ;?: :?;
to ^ -^ O Tt< Tf
CO ■* CI to ■* •<)'
I to to to to to to
I IN IN C) IN C) IN
Tf rt T«< O O iJH CO
-!l< C) -^ CI o ■* to
( to to to 00 X to I^
t IN CI <N (N O C) IN
-H 1)1 00 t^ -H rt
O IT CO CO O CI
to to to to to to
O C4 O IN C) O
to to CO CO CO CO
to to -^ If -^ ^^
t^ t^ r^ t~ t^ 00
TjHT)<r^t^oooococoeococococoo5C»050ios05aia>05050s0505ai coeocoeoos
0>050000(NOdOO(NCHOOOOOOOOOOOOOO
CDtOt~l>-t--t^t-t-t»t-t-t^t^l-»t>-N-t^t~t-t>.t^t-t^f~t~l^t^
O O O O to 00
1^ t^ t^ t^ to to
to to O O to to
to -< t^ — • iji "*<
■* to Tt< to to -^
O CJ CI O C) ■-<
-I .-I -H ,-, .-H •*
eg CI o d C) c)
fS^fS^s:^ ^^tS^Eg^^^^^^^^fSgriS^tS&^tS^P^^fS^fSp: jS is ts ts is ^
CCCOOO'^'^'^'^'^'^'^-^'^OOOOOOOOOOOOOO
0000"^"^-»t'^"^'^-rt<-(f-.^00000000000000
o o o o o »o
O O O O CM CC
^ ^ t>l M ^
t-H .-H Oi C^j C^I C^l C4 (N CM Ol (M (N 'M <M <^^ CM CM CJ CM CM CM CM
ZZZ^^^ :2; :z; ^; :z; !z; ^ ^; ^; Z ^ :z; 12; 12; g; iz: 2: :z; ^ Z ^: ;?; 2; ;z; 5?; I?; I^: ;?; :?; ;? ;z; ^; Iz; ^z;
»0 lO lO lO >0 CD
CO CO CC CO CC "^
CO CO CO CO CO '^
C^J CM CM CM CM CM
O O Ol O: X 00 00 CO 00 00 X CO 00 >C lO »0 'O i.O lO »0 »0 lO »0 lO *0 >0 'C
ooooooooooooooooooooooooooo
COCOC0CO'f-^'^'^Tt*-^'r^"^"*COC0COC0C0COC0COC0COCOCOCOCO
CM CM CM 04 CM C^l C^l CM CM O) CM CM CM CM CM OJ CM CM CM C^l C'i CM C^J C^J CM C^J CM
lO iC 1-0 »0 "^ •— '
^ ^ ^ ^ C-i -^
CO CO CO CO 'J* -^
OJ CM CM Ol CM OJ
i-H 1-H CO CO CO Ol
,— I I— ( »-< 1— I 1— I CM
r^' ,^' ^' ^ '^^ '^'
«o 3 3 "3 ^3 3 3
*o >-i *~i ^ ^ ^ ^
COCO!>t^OiOlOOOOOOO'-<'— "i-Hf-Hf-l^r-t.-li— t.-!.— I.-H^.— (
CMC^^CMCMCM(^^COC0COCOCOCOCOCOC0COCOC0COC0COCOC0COC0COCO
;>.
>^,
'•^,
>,
>.
>i
S^
>,
>.
s
ca
03
01
03
a
CO
a
03
03
03
03
r'i ^- r^
O3c3o3c3c0o3o3o3cdci3o3o3o3o3o3o3ci3ao3c3o3o3fl3c3o3p3o3
Ttl to
lO >< r^ << r< << f< r<k ><^ f'. ^^ << ^ f< '^> >< << << <"■ <' << <'<
<', ^. r*. 1^. <', r^.
Gi cj 4j aj Qj cj
s c c a c c
3 3 3 3 3 3
t-: ^ )^ t-s •-= t-j
854
CALIFORNIA FISH AND GAME
On
to
«
m
lO
o-
'' —
■o"
-D
<u
(U
->
=3
C
0^
c
n
ro
U
1 —
1
o
CO
Q.
X
-a;
Q
Z
r-j
II 1
i_
Q_
o
Q_
fU
<
fU
a)
o *
g §
(D
■«
01
g
.^J
(»
aj
s
M S
T3
3
-*^
o
>-l
c3
C3 g £ O
M g 3
X
,^^
-*->
fl
tn
bO
Ph
0)
d
o
3
C3
63
Q
fQ ccmw ffl
pq Ph fflffl pq
P3PQa}cceQmSP:7-jKffifflfflffla:'ffl
ff5fflci.PHmc3ffiP5;uffipqp3mp3PHpQ
M M W K' CC M
Ph fL, pq Ph Ch a,
O 05 O 00 ^
00 00 lo
ooooooooooTfroeo
'f J*. O CO O t^ C^ C5 CO O O
— 'Ml' -H -- ^
(N (N O f -* CO
»0 C
CO LO
(N Oi "^ CD O^ (N
•* 1^ r^ O ■* ■*
CD o :c ;c cc :r:
Lo 00 CO 1
p 1 en o
UO (N Tf>
1 t^ 00
cs CO 00 1
1 1 o ■*
O to 1-1
1 <o o
--TO-*
LO LO
CO »o to
lo m
O CO O "O Tf
CO t-H .-H CO
ic-)OooQOO^cot^co02-H
cococo-^cnoooc^c r-
Tf rf — .-H l>) (N
feS:l
: fe fe; I
»o »o ^ o o
'H CO ■* ■* CO
CO CJ .-H IM ^
CO C] OJ '1' O O IM OJ O lO lO
CO.-H.-I— i^OCOt-iCOiMi-i
COCOOI^OOlOOCOOICOOO
o CO
Oi O; O C: t^ CI
o o o o o c
CO CO CO CO CO CO
^z.lz.'Z.'Z.Z
■M O I^ M O:
"O »0 CO lO o
"O ■^ CO 1* ^
<N C^i W C^ CM
iz; Z; 2; ^; ^ 2; 2; Z 2; Z ^;
LO o 00 o m en — ' o 00 CO i-o
OCOt-^C^lO — CMCOOcOO
I CO "O 00 oa C-4 t^ 00 lO -^ O O)
iCS<MlNCMCOtNCMlN(NCMCO
22; 22;2;222:
Tt<CO T)<Tt<Tt<Tl<^CO
lO 'J'
to LO to to to 10
<N N CM (N (M !N
OOOOOt^. rtO3O3C»O3O:t^t^C000t^[^t^t^C0
00 t^ t^ o o
CO CO CO t^ t^
l^cocccococooooooo:— ■— c — -HTtcO
cococDcocooocococot^t>-r-t>-t^co
00 00 00 00 00 00
00 00 00 CO CO CO
t^ t^ t~ t^ c^ t^
^^^^^ >^^^^^^^^^^^^^^^
>:^^^
to to to to to
CO CO CO ■* ■*
a^cocooocoocroaic35cno;co
'-HCOCOC0COCOCOCOCOC<)^'-^ — i-iOCO
t^ t^ t^ oo 00 00
o o o o o o
CMOJOICMCM Tt<-*-*-'*<i*-*-^T}<Tt<Tt<'*Tt<TtlTt<CO-* COCOCOCOCOCO
2:2;2;22 2;2;2;2 22;2;2;2;2 22:2 22:2; 22;222;2
rt rt 1-H CO CO
-*< Tjt T»< o o
"^ -^ TjH to to
CM CM CM CM O)
— to to to to to to to to CM CO CO CO CO t^ to
OrH,— — i-H^t-H.-H^CM'-'^ — '-H'^tO
COCOCDCOCOCOCOCOCOCOCOcOCOCC'tOCO
CMCMCMCMCMCMCMCMCMCMCMCMCMCMCMCM
^ 1* 00 o o o
^ Tt' CO '^ '^ ^
to to to to "O to
CM CM CM CM CM CM
CD t^ t^ 03 Oi
rH 1-H 1-H CM CM
1> dt C> G^ Q^
c; c c c c
3 3 3 3 S
•-5 1-5 >-= P-J ■-=
I O Tt> ■<*< ■* -^ CO 00
,-HTj<Tj(Ti(TlHTj<CDCDt^CqC^CMCMCMCMCM
oj CM CO to in to
hi hi) bL hi) bi bi
3 3 3 3 3 3
<;<;<: i; -< <il
TUNA TAGGING
355
CO ffl
mpq
fflpqaJiBfflfflcQCQfflfflKPC
eqmmpqpqpqcQpqoqpqpQqq
X, pq cQ , ,yj m
a fflpQ ipHpa
eocoa
m 2-(P5
oooooooooooo
00 '!<
I O u^ (M CD
I PO to 1^ '-I
00 CD I 05
O CO I tD
00 1
1 1 r.i
00
1 IN
O 1
1 1 lO
CD
1 CO
CD
IC
lO
«o
1 t~
00
(N
Ol
IN
O)
O)
O]
Ol
on
^
^
00
00
00
CO
t~
CD 1
1 t-
00
CO'
1 T-H
>o <
1 M
1— <
CO
Ttl
1
t-H
1
1— 1
1
'I'
^
m
1
<N
CO
1
CO
CO
CO
1
CO
CO
1
CO
(N
CO 1
1
■o
00
1 o
r~
CO
r lO
^
^'
^>'
^»»»>'tS>»"
K^
^
^>"
!^
^
^
^
^
^
^
^
^
^
^
^
^
^
V
^
^
^
^
V
^
V
V
V
-
-.
a
ro
(-:
^
CR
05
05
Hi
m
>o
05
CT>
en
Ol
a:
05
CD
00
00
o
^
CC
o
O
lO
o
O
o
o
O
o
C-4
o
O
o
o
o
o
O
CO
T"*
CO
"^
•"■
^
o
n
o
o
o
0
o
o
o
0
o
r^i
.— 1
IN
<N
IN
(N
(N
OJ
CO
CJ
CJ
O)
CJ
l»
C^
CD
CD
CO
CO
1^
^
>— (
I— (
i-H
.— 1
>— I
T-H
T-H
O
O r
1 O
o
CO
1 rH
T— 1
1— 1
I— 1
i-t
rH
f-H
rH 1
I-H
■Z.Z '^■z
o 00
O 'O
o 00
o o
^; ^ 2; ^; :z; 2; ^; ^; iz; :z; is :?: Z ^
OOOOOCDOOOOOO 'O o
OOOOOCOOOOOOO o ■*
oooooooooooo o o
GiOld'OlOl'-OOiOjCiOJCSO^ T-H rH
rHrHrHrHrnC^l-HrHrHrtrHr^ (N C^
iz;^
00 lo
^ z
o
Ol
/^
CO (N
rH (M IN
CO CO
00 00
lO lO lO »o »o ^ 1
0505050i0505OOOOO05
t^f,t^t^t--t^oocooooooot^
00 rH 05 0> 02
t^ 00 t> t^ t^
Tf IN Tt<
00 00 00
CO
00
00
0 o o o o
01 lO t^ 00 Ol
CO O CD lO CO
o
■o t^ o o o
o to «o
o
t^ O CO CD CO
f CO CO
CD
lO lO "O to »o
^^^ '^^ ^^^^^^^^^^^^
00 (N lO
lO lO 'f
0i01050iO50501Ol05O50>05
oooooooooooo
IN O) 01 IN Ol Ol IN Ol Ol Ol Ol Ol
^
^»'
'^
is
is
^
s:
'^
^
^
^
^
^
^
^
^
^
^
•-
t-H
-f
<->
o
O
O
■o
•— 1
c;
CO
ic
lO
CO
CO
CO
CO
CO
T— '
•— '
o
r-l
o
n
o
o
o
o
o
0
0
o
»n
CD
f-i
rn
CD
CO
CD
r^
^
n
o
O
O
OO
00
00
00
OO
"O . . .
O lo t» CO
nl "O If -r
^ o o o
■5 00 00 00
^ rH rH .-(
CO 00 00
01 IN 01
;o 3 3 3
10 ^^ ^ ^
00 oooooooooooo
00 oooooooooooo
00 oooooooooooo
CO
0 10
'Z 'Z, 'Z ^ ^
I'A^^
S'.
rt< CD CO CD CD
0 'O «.0 i-O 10
01 0 01
-H CO .n .0
01
.y 0
X 0
<u 01
00000
Ol rH rH -H rH
01 01 Ol 01 01
Centr
10°
11°
08°
h
,_,,_|.— t.-H.— Il-H.— 11— ll-Hl— I,— ll— I
K3c3o3o3c3c3rarao3C3C3C3
.— (
(N CO CO PO CO
05 ^ 01
si
cj 0 0 0 0
Qj a> Qj a; 0
QOQQQ
L^ Ui L-
_. a a a
w
CO
0
T3
rt
^^
3
i-i
M
00
IN
>.
C3
CS
t" »-H
■^ >r<
s ^.
10 f^
o>
91
356
CALIFORNIA FISH AND GAME
oi
o
U-)
o
—
■o
-D
0
3
=
C
^
C
o
ro
U
•"
tf
c
m
OJ
Tl
it
o3
2
Q
+s
X
*^
^
w
bl'
f^
;^
C3 >i
CO .^
X wo
Q- £
< re
>-
s»
o
o
3
03
_c3 g
tf
CT3
fe
T3
3
'5b
o
-0
3
si
►4
P3 pa
»
Pu
mo
ffl ffl
. ffl
■O CO
CO 'O
» ffl
ffl
m
05 ffl B3 1
o >o
t^ CO
CO
r 1 X (M
1 1 ■*
lO
CO
1 02
Of)
Ol
1 00
■*
■*
't
o
^^
CO 'O
o o
^^
o ^
00 00
00
(N
-I 00
CO Tl"
CO CO
o o
CD
CO
CO
o
-H O
CO CO
CO CO
o o
o
00 00
03 O
CO r^
o o
«o o
CO 03
!s^
^ ^!S
^ ^^
O OCi
-H 00 00
rt o o
O) C-l
o o
!M Ol
o o
b
«
<N IM
^
'— <
p
967
July
July
> >
O 0
lo O O
o
o
00 -H
0) OJ
QQ
O CO
O -f
o o
to >o
!N O
I CO Tfi
I o o
T)< rt CO CO
CO ^ ^ ■'t^
t>. t^ t^ 1^
^^^^
05 CO 00 00
iM lO O O
-^ O ^ '-<
00 oo 00 00
02 05
03
OQ 03
S WM
m
m m
CO
mmmm
t^ CO
CO CO
s
1— ( T-H
ulf of G
03° 13'
03° 13'
b
CO
00 00
b
CO
lO (N ■* T)<
rt Tj< O) !N
o o
.— 1 I— 1
o o
o
o
o o
.— 1 T— 1
O O
o
CO
o
o o
O O
o
s
o o o o
^ CO CO CO
O O O O
O
rt (N (N
00 -H rf rt
+J +i +J
o c; cj o
la 1
TUNA TAGGING
357
03 a O CQ
ffl CQ P3 pa
ffiajffiocmfflofflaaoofflooaooo
mmpacafflpampqmfflpaaapacafflfQpacQ
, P3 OOO CQ CO
, fflpammm ffl
i-(CO'-'CDCOXX'-'^XO'M050CC05Tj^tN.c^tN.iOOOr^C^(N^OM
, ffl O O K O oq
,p5«mpqmcQ
,00
,0
'C^CO •"O-t00c«5>OCC0000-^O>
t o o
00 -H
1 00
10
1 0 1
1 1 0 0 1 1
1 1 01
r f-H
' "i
1 N
1 1^ 1
1 1 Oi Oi 1 1
1 1 CO
1 1— I
1(5
■0
Tt< Tf
'I'
in
■* c^ 10 CO 10 «o 10
•>*< 10 00 IN 10 M ■<)<
CO <-» (N o --H 10 f-H i^ o o; o 10 ^ CD
I'OMCO'* — t^C-JCMCOOOOOOOO
iTfOCCOt^^^-^OlO^iOW
^ Ol I I I „
CO 05 CO
-^ CO 00
^^^^Sr^^^^^^^^^^^^^^^^^^^^^^fc: ^>' ^»">»»»-
^OCOr^O^ — QOO'MC^JOOiCt^OiOC'l'NCDiOiO'MCDC<)0(N05 0:D
o<-"c^iooc^oioO'-''^ocmi^ioc)0'-hO'^iciO'-ho^oc^-^ 100
0000000000000000000000000000 00
oooooot~oooooooooooo«oDXooooocoooooooooor^oooooooooooo 10500
00 iM 00 c-i o) t^ a> to t^ -f
lOOiO'-'^OiOiOOO
loooooooooooooooooooo
aj t/i 03 Vim aim x" czi x' ai oi a.' ai c/i a." oi c/i tzj oi aj cc oi ai ai m ai aj 1^ 1
inmminirimmmviiri
aDOOiC—iOOtD-<l<CD(N'*OiOt>.C00305t-e^iOOTt<lNiO'^'^iC05 OiO
iMcO'-'C-«i'C-je>)coicc^coo — — <C'iOf'-'C>4rtioocoocsi^!Ncs 00
0000000000000000000000000000 00
COCO'l'05COCOCOCOCOCO'*<CO'*<COCO'^COC^CO-*'M05CO-*COeO'*CO ICOt)<
OOOOOOOOOOOOOCOOOOOOOOOOOOOO lOO
•^■*OiOC^t^t^O«OOs
C0iCOOC0i0iC'<l"O'*
COCOCO^COCOCOCO^CO
0000000000
cocococ<i(N'*Tj<o5'j<Tj'o>o30>05t~t>.t>-t>-t>.o>050>0305aiOJ050505i>-t»i-»t^f-TfT)<Tjit^cor~r~b-
1^ t^ r» (^ r^ t^ t~ t^ t^ r^ t^ t^ t^ t^ 1^ t^ r» 1^ r~ r^ r^ t^ r^ 1^ t^ t^ t^ t- t~ 1- t^ f» t» t~ r» r» t^ r^ t~ i^ \~ t»
^'
^»»»'
^'
^' ^ ^ ^' ^' fs i
^'
^»»>'
^'
&:' £g:' ^'
is
js
is
S:'
fs
?J
•s
is
is
^'
is"
jS
^'
is
is
'N
•M (N
c^ c^
Oi Oi <y.
CO
Oi C^^ (N
(M (N X X
00
X X t^ t^ t^ r^
(^
t^ r~ i^
r~
r^
UD
0
Q£
^
!C
ot
01
C^*
Ol
CO
0
0
0
•— '
.— 1 .— 1
-* -^
C^ Z^ Q^
CO
CO Tp -^
■^ -^ CC CO
CO
CO CO CO CO CO CO
CO
CO CO CO
CO
CO
CO
CO
CO
CO
CO
-1<
f
Tf
■*
0
0
0 0
0 0
000
0
000
0000
0
000000
0
000
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
00
X X
X X
XXX
00
XXX
X X X X
00 00 00 00 00 00 00
00 00 00 00
00
00
00
ooooooooooxoonoo
00
00
00
CS'N<NC^)CSCOCOC0COCOCOCOCOC0'-H---'i-'^.~''-«^i-Hw^,-.^^^»-i.-H.-^^^^.--.^.-ii-.cO^'--"«-"
000000000000000000000000000000000000000000
C0COC0Tt''^'^Tj^TfTfTt*-^-<f-^-^Tt^Tt*TfTt^'<^TtHTt*Tj<-^-rt<-^Tt^TtTt'Tt^'r^Tj<-^Tj^'rt*'.^Tf
000000000000000000000000000000000000000000
cococcxxxxxxxxxxxososaiaiOioioso505a:05a50soiOiOiOiaiOiO>oooocot-*i--.r*
^-3 -tJ >3 >S -»J +S +S
-fi -*i +3 +3 -»J
+j +J. -W +i +J
+i.+J+J4J-*_>+3+3+J-|_>
000000000000000000000000000000000000000000
358
CALIFORNIA PISH AND CA.ME
ro
uo
O
■^
-a'
-o
a>
1)
3
c
Of
c
n
fu
U
•"
CO •£•
-x»
IX^
Q
Z
I —
LU
CL.
o
<;*^
ra
Q:J
rt
T3
3
'm
c
o
0)
K
w
<D 3
01
to M
0)
T3
3
'm
CI
o
►J
0)
-a
3
1-1
« 03 ffi a o cq , o
P3
pa
o
mm
m m
mm
m m mom m
m mmmmm
■* CO O
•t oi o<
-^i ^.
IM CD
1 rf
1 lo 00 in
^
o
lO O)
,-H
1 ^ o
00 00
' <N
1 TO to 00
04
-H C^
»l
1 CO •-'
^'
1
o
>, <D
03 X!
P =
^^^^^^^^ is
p::S
^^^
(N t^ C^ O) lO O >0 lO
o
0000000000000000 oo
o
00
CD t^
lO lO
fe
C5 O
to »o
o
r^ ^ lo
CO >c m
o o
o
o o
1 O 05
1 00 r^
o
o o o
1 -H oi Oi
< 00 t^ t^
m rn yfj m -fi m m m
■-ir^cMio^iMi^O
TOTOCOTOTOTOCO-*
OOOOOOOO
ai'
m
■Tj M
m
Oj 02
m
mvim
00
<N
O O
in
6
CO -if
O O
o
o
04 -f Tf
-H o O
o
8
0
8
o o
n
(35
O
0 0
;s§
c
O
O 0 o
1 Tt< 05 03
1 O O O
l^CDtDOO'-H'Hi-l
— <-H-JTOCO<N<NCq C-)
CD
t^ t~ TO "O
00 00 00 Tj< Tt<
C-1 CO
Tl< -P rf Ol lO in lO lO lO
t^ 1^ t^ t^ r£, tQ to 50 tQ
^^_ooooo o
oooooooocooooooo
^'
^>'
^»>'
^' ts' ^' ^' ^'
00
o
C^l O
I> t^ t^ i.O
lO lO O lO
CD CD CD Tt< Tf
TO TO CO TO TO
o
5
o o
05 O
o o o o
G2 CI O Ol
t^ t^ t^ t^
o o o o o
05 05 05 05 05
1^ r- t^ t^ t^
mmoimmxnmm
CD C^ C^l CO CD IM C>) "N rt
C^OaC^TOTOTOTOTO TO
OOOOOOOO o
w
5 03 02
O)
Hi i!0 00
goo
TO
o
_ O 0
TO
3 05 05
O
ir, o =>
mmmm mmmmm
TO TO TO TO
o o o o
05 05 05 05
o o o o
TO TO TO fN (M
05 05 05 05 05
o o o o o
<x
(NC^OQTOTOTOTOTO
+j -t-i -4J -t-J +J -*J -tj' -fii
OOC5C5t5C5C5C5
OOOOOOOO
(N (N
>
o
05 a)
a c
OJ 03
^^—.05 05
+> +J -t^ -*^ +J
n a a ft a
05 05 15 <I> C
mmmmm
TUNA TAGGING
359
cacQoaacacQCQcQcQfflffloaffloaeQmeQDa
OOOOOO'^TfOOCOOOOOOiMC^OiOOO
C^»0»0^0'OOOCOOCOO_L
o o
1 o iC
CO
< o a oi
CO CO
t-QtO'-OCDCOCDCJOSr-^— *'-'— 'COCOOOt^^H
I „ ^ ^ r-< r'\ 01 -» C-l C^l <» C-l -t t^
CO I I I I I I I II
t^OOOOC^i'M OCO
,-H-Hrti-Hi-Hi-l coco
■^ 'M CI CD 'O --^ O 'O CI »0 iC CD a: tM '
1 OJ 1^ »0 CD t>-
OOl^MCD lO-f-fiOTtiTfOOCOTf 1
1 (M 02 CO -t< -f
^^_|rt,-lrt,-,_rHrfrt 1
1 t, 1 1 00
1
^ o m .-1 CO
CD
CO
r-H CO ^ .-.
•-H
*<i '<.'<. ^
^^"^^*^r:t^^^^'
'OiO»OUOiOCO'-i'-^00000'-H^iQiO>0
i^t^t^t^t^ooooc»oooooooooooooot~oooo
s::^
li •* li -i ti -i -^
^IS
omoomooooo^
ccoooooot^oooooooooooo
lO --1
t^ iQ CO
■O O O
O 0
O 0
1 en -H
1 t~ 00
o o o
1 C6 -"■ O
1 t~ 00 00
mmmiriinm c/i ui ai ai ui c/i m tzj m czi a5 w co ai cc <vi c/i r/j aimm mm S aJ aj w" w m vi c/i
»0 'O 'O 'O <0 O C^l C^^ 00 CD CD CD CD OJ OJ O CD "t
OOOOO^COCOC^IMOaOllMCOCOOCMCO
aiOicicrjOicocococococococococoaicoco
oooooooooooooooooo
tHtHcooioco— 'coocDOrvjiom
lO^o-HO^O'-'co^co^oo
ooooooooooo^oo
COOTt^^Oi-tHCOCOCOCOCOOOiOi
ooooooooooooo
lO CO
O CO
I 01 CO
I o o
lO lO 00
O O CI
I O: -^ CO
1 o o c
O (N O d d (M IM d !N C-1 O) C) CI O) O C) CI OJ
CCCDCDCDCDCDCDCDCDCDCD'CDCDCDCDCD'CDCD
to lO CD to >o 'O »o »o »0 lO to lO CI CI CI CI C5 CI CO CO CO
CDCDCDCOCOCOCDCDCDCDCDCDCDCDOCOCDCDt^t^t^
:^^^^^i
»0 »C LO »-0 to lO lO *0 lO lO lO »0 to »0 lO lO »o »o
:r-*i<-*<»^f<-:r»^»^i-r»---
^?:-:i^^^^^^^
u0LO»O'-HiO'O*O'O»O»^iOiO»OtO»C»O»O>O»O'O»O
010i03 0010501030>030)0>010iOi010303010303
t^t>i^oot~t~t^t^t^t^t^t^t^t^t~t^t^i^t^t^i^
Hi mi V2 mi m ^i m !jj V2 m m m m rji viiTiin m
»0 »0 «0 to to iQ lO 'O »o >0 'O 'O «0 'O 'O 'O >0 'O
oooooooooooooooooo
m m mm m mmm m mmmi m mm m mi mi m m m
»0 lO »0 CD 'O lO iO 10 lO lO lO iO lO »0 >0 lO 'O »0 'O 'O 'O
ooo oooooooooooooooooo
O^ O'j O^ 'O Oi Oi ^ O'j Oi ^^ Ol '^ Oj Oi Oi Oi O^ '^
oooooooooooooooooo
ooooooooooooooooooooo
IO »0 LO 'O "O »0 'O "O »0 IO 'O »0 IO »0 LO lO IO LO
oooooooooooooooooo
Tt^ to CDOOiOiOsOlOl'
OOOb-t^l^t--t^l^000000
t-i L. L^ t-. L^
360
CALIFORNIA FISH AND GAME
o»
LO
cr-
^-
jc
O)
3
o
e—
>—
m
vo
o
—
■o
-o
0
^
-)
C
Of
4—
c
O)
o
u
1
c»
fO
CO
a.
X
Q
1 —
Z
rvl
UJ
Q-
^
Q.
<
ro
a
s».
a>
»
o
<^
<u
a:
-a
>s
a>
n
a>
>.
t4
« *
> s
«
«
03
03
tf
m
«
03
03
§■5-
0
0
0
(N
g|S
*^ > '3
.2 g S
Q^-
CD
Ol
t~
,
05 bo S
00
0
00
1
■^
10
"t
ESS
^^
t^
t^
CO
t^
d ^
1
f-H
•*
!; -^
•n
>»
(C ^
t^
>. 4)
0)
03 J
0
Q-
o
a)
,
,
-d
js
t£
tS
cs
-*j
■3
1^
0
^H
*— I
CO
0
C)
CO
0
0
0
0
0
1-1
(N
1— t
00
Oi
02
OS
00
0)
T3
z
•^
02
Is'
+J
^
^
^
^
'*J
CD
0
CO
CJ
03
-*
CO
CO
h-1
0
0
0
0
0
0
■0
0
0
0
0
It)
tH _
1
face
ratu
:rees
.)
1
^H
CD
CO
t-
t~
00
S al^
M as
B
0
0
10
0
^57
03
0
0
CD
-*•
lO
10
lO
m M C3
'^ §^
(P
T3
~»j
is
Ss
is
is
^
^
^
^
V
P
■3
c
t^
Q
.—1
"f
^
CO
0
-ri
CO
D
0
0
0
0
—1
0
00
03
03
02
Oi
00
0
f2
;_
ts
OJ
tf
^0
•0
0
a
0
0)
-a
.2
m
M
to
So
2
b
CO
la 0
0
a
T(<
CO
•-I CO
.4-3
hJ
P.0
0
0
So
c« 0
0
0 lO
,rt
•3°
0
0
0
§0
0
«
1
jj"
a»
C
1
OJ
1
to
^
!N
0
'
00
a>
03
<N
(M
-N
cs
"
Q
J2
0
u,
J2
5
0.
S^
a
'&<
1 ^
o>
o>
1 ^
iH
iH
*
TUNA TAGGING
361
APPENDIX C
Number of Pacific Yellowfin Tuna Tagged and Released by Area
(One-Degree Square), Month and Year
Year of release
Month
of
One-degree
square
release
1952
1953
1954
1955
1956
1957
1958
1959
28N-118W..-
Aug
3
28N-118W.__
Oct
1
27N-114W.._
Aug
28
27N-114W.-.
Oct
11
27N-115W_--
Sept
72
27N-115W.__
Oct
2
26N-113W__-
Aug
61
26N-113W^--
Oct
189
26N-114W_--
July
185
26N-114W_.
Aug
47
26N-115W___
Oct
64
25N-110W_._
April
1
25N-112W___
June
22
25N-112W_-.
July
7
25N-113W___
July
7
3
1
25N-113W___
Aug
177
25N-113W_.-
Sept
40
25N-113W.__
Oct
11
1
24N-111W___
May
42
24N-112W_-
June
38
24N-112W___
July
241
24N-112W___
Sept
5
190
23N-111W.^_
May
299
23N-111W_^-
June
45
99
23N-111W___
July
104
7
23N-111W.-.
Sept
153
23N-112W__^
May
96
23N-112W___
June
20
23N-n2W__
July
399
23N-113\\\-.
July
29
22N-10f)W___
Nov
6
22N-108W_-_
Feb
'>
22N-110W.
May
5
22N-110W.-_
June
13
22N-111W___
June
130
9
22N-111W_._
July
160
22N-112W___
June
75
22N-112W__-
July
44
22N-n3W,_.
July
8
21N-106W.__
Jan
6
21N-106W___
May
2
21N-100W_..
June
43
18
21N-106W.-_
July
87
21N-106W__.
Nov
38
21N-106W_._
Dec
16
21N-108W__.
March
10
21N-110W__
May
1
21N-110W___
June
12
20N-105W_._
Nov
27
20N-106W__-
Feb
1
20N-100W_„^
May
2
20N-106W.__
June
1
84
20N-106W___
July
6
20N-106W._^
Nov
12
20N-107W___
March__.
4
19N-104W._-
April
4
19N-105W__.
March
26
19N-107W.__
June
3
19N-111W___
July
1
19N-111W._.
Aug
2
19N-111W__^
Sept
43
19N-112W___
May
99
19N-112W.._
June
15
19N-112W-__
July
9
18N-103W...
May
43
18N.103W.-.
1 June
1
6
■MV2
CALIFORNIA FISH AND 0A:\IE
APPENDIX C-Continued
Number of Pacific Yellowfin Tuna Tagged and Released by Area
(One-Degree Square), Month and Yeir
Yeir of release
Month
of
(Jnc-degree
square
release
1952
1953
1954
1955
1956
1957
1958
1959
1SX-104W___
Feb
7
18N-104\V...
March
2
18X-104\V__
April
1
I8N-104\V_._
May
5
27
18N-104W_._
.lune
16
18N-107W_._
April
1
18N-110\V_..
Mav
13
18N-111\V___
July
11
18N-111W__
Aug
1
18N-111\V___
Sept
50
18N-n2W___
July
6
18N-112W___
AuK
1
18N-114\\\__
May
117
18N-114\V___
June ._
120
8
60
17N-101\V___
Feb
67
27
17N-101\V___
Ai)ril
26
17N-101\V._.
June
115
17N-102\V_._
Feb
17
168
17N-102\V___
March
3
17N-102W_.^
April
188
17N-102W___
May
1
17N-102W^^_
Nov
15
17N-103\V___
Feb
39
17N-103\V...
March
8
17N-103\V___
Mav
10
17N-104W__
Feb
48
17N-104\V___
May
2
17N-10.5W_-
March
3
17N-105\V^_-
April
5
16N-98W
June
13
16N-99W
Jan
2
, 4
8
16N-99W
Feb
2
lfiN-99W
March--.
39
16N-99W
April
5
16N-100W_.
Jan
18
2
16N-100W___
Feb
1
40
)riN-100W__.
March
6
16N-100W___
April
3
1()N-100W__.
May
3
](iN-101\V._^
March-..
33
ir.N-101W__
April
15
ION-101W__.
Mav
10
6
16N-102W.__
Mar-h...
24
16N-102W_.-
April
7
1
16N-103W._.
.March...
3
2
16N-103W__^
April
1
15N-94W
March _ .
23
5
15N-95W
Mar-h- _.
17
1.5N-9.5W
May
18
1.5N-97W
Feb
29
5
I0N-97W
March
16
51
I0N-97W
April
77
15N-98W
Feb
20
1.5N-98W
March
40
15N-98W
April
57
3
15N-99W
Feb
33
1.5N-99W
March...
3
15N-99\V
April
8
1.5N-99W
Nov
10
loN-100\V_.
March
6
ir)N-101\V_ _
March
31
loN-102W__
March
5
14N-92W
April
2
14N-92W
May
1
I4N-93W
March
6
I4N-93W
April
7
TUNA TAGGING
86.S
APPENDIX C-Continued
Number of Pacific Yellowfin Tuns Taqged and Released by Area
(One-Degree Square), Month and Year
One-degree
square
Month
of
release
14N-93W
14N-94W
14N-94W
14N-95W
14N-96W
14N-96W
14N-97W._-
14N-97W___
14N-98W.__
14N-98\V_._
14N-100W_-
i4N-ionv__
14N-101W__
13N-89W___
13N-90W.._
13N-90W___
13N-91W._-
13N-92W_^_
13N-92W___
13N-93W^-_
13N-93W__.
13N-93W___
13N-93W___
13N-94W___
13N-94W_^_
13N-9.5W-_.
13N-9.5W___
13N-96W___
13N-99W__.
13N-101W.-
12N-87W___
12N-87W__.
12N-88W.._
12N-88W...
12N-88W___
12N-88W__.
12N-89W__.
12N-89W__.
12N-89W.--
12N-89W__.
12N-90W__.
12N-90\V__,
12ISr-90W__.
12N-90W^.
12N-91W_.
12N-91W__,
12N-91W„_
12N-92W...
12N-92W._.
12N-93W^_
12N-93W._
12N-110W_
11N-86W_-
11N-86W..
11N-87W..
11N-87W..
11N-87W__
11N-87\V__
11N-88W_.
11N-88W._
11N-89\V_
11N-89VV__
11N-90W__
11N-90W_.
11N-92W_.
11N-93W..
May
March
April
May
Feb
April
Feb
June
Feb
March
Feb
Feb
April
April
Feb
March
March
April
May
Feb
Mareh__.
April
May
Feb
April
April
May
April
Feb
Feb
April
May___-
March. .
April
May
Oct
Jan
Feb
March __
April
Jan
Feb
March- _
April
Feb
March- _
April
Feb
March- _
Feb
March- .
Oct
Jan
May
Jan
March--
April
Oct
March-.
Oct
March-.
April
May
Oct
Feb
Feb
Year of release
1952
1953
1954
1955
81
r.7
40
8
16
69
16
5
112
5
52
28
133
11
9
4
3
38
9
1956
4
38
3
91
51
14
40
12
1957
1958
1959
1
78
5
7
174
9
9
34
54
85
33
1
12
1
6
4
30
1
16
14
18
17
236
20
31
14
251
1
41
40
57
22
364
CALIFORNIA PISH AND GAME
APPENDIX C-Continued
Number of Pacific Yellowfin Tuna Tagged and Released by Area
(One-Degree Square), Month and Ye^r
One-degree
square
Month
of
release
Year of release
1952
19.53
1954
1955
1956
1957
1958
1959
10N-86W
Jan
10N-86W
Feb
10N-86W
March
10N-86W
April
10N-86W
May
10N-86W
July
10N-86W
Oct
10N-91W
May
10N-109W_..
Jan
10N-109W___
Feb
10N-109W.__
May
10N-109W...
Oct
09N-85W
Jan
09N-85W
Feb
09N-85W
March
09N-85W
April
09N-85W
May
09N-85W
Sept
09N-86W
Oct
09N-88W
Oct
08N-79W
Feb
08N-83W
Feb
08N-83W
Oct
08N-83N
Nov
08N-84W
Jan
08N-84W
March
08N-84W
Oct
08N-85W
March.. _
08N-85W
April
07N-77W
Feb
07N-77W
April
07N-78W
March
07N-78W
June
07N-79W
Feb
07N-80W
Feb
07N-81W
Jan
07N-81W
March
07N-81W
July
07N-82W
Jan
07N-82W
Feb
07N-82W
April
07N-82W
July
07N-83W
March
07N-84W
Jan
07N-84W
Feb
07N-86W
March
06N-77W_._.
Jan
06N-77W...,
Feb
06N-77W
June
06N-78W
March
06N-78W
June
06N-79W
July
06N-82W
March
06N-83W
Jan
06N-84W
March
06N-86W
March
05N-77W
Jan
05N-77W
Feb
05N-77W
March...
05N-77W
June
05N-78W
Feb
05N-78W
March
05N-80W
July
05N-82W
June
05N-87W
Feb
05N-88W
Feb
05N-88W
March
139
12
37
37
48
6
23
0
12
89
o
14
27
18
2
6
1
1
f)l
137
2
1
12
21
29
7
11
2
6
24
07
77
15
202
5
3
11
14
6
7
43
3
150
1
31
15
12
15
TUNA TAGGING
365
APPENDIX C-Continued
Number of Pacific Yellowfin Tuna Tagged and Released by Area
(One-Degree Square), Montli and Year
One-degree
square
04N-78W
04N-80W
04N-86W
03N-81W
03N-90W
03N-90W
02N-78W
02N-78W
02N-79W
02N-79W
02N-79VV
02N-79W
02N-91W
02N-91W
01N-79W
01N-79W
01N-79VV
01N-79W
01N-81W
01N-90W
01N-91W
01N-91W
01N-91W
01N-91W
01N-92W
01N-92W
01N-92W
00N-80VV
00N-90W
00N-91W
00N-91W
00S-80W_
00S-89VV_
00S-90W.
00S-90W_
00S-91W_
00S-91W_
01S-81W_
01S-81W_
01S-81W_
01S-81W_
01S-89W_
01S-91W_
02S-81W-
02S-81W.
02S-81W_
03S-80W_
03S-80W.
03S-80W_
03S-81W_
03S-81W_
03S-81W_
03S-81W,
03S-81W_
04S-81W_
09S-79W_
09S-79W.
09S-79W_
09S-79W.
09S-79W_
09S-80W_
19S-70W_
20S-70W.
20S-70W_
Totals...
Month
of
release
March
July-.
Feb.._
March
Feb. . .
March
Jan
May. _
Jan
Feb. . _
May._
Dec...
March
Sept...
Jan
Feb...
May.-
Dec...
Dec...
March
Feb. . .
March
Sept._.
Dec...
March
Nov...
Dec...
Jan
March
Feb...
March
March
March
Nov...
Dec...
March
April..
Jan
May..
July..
Dec...
Nov...
Nov...
July..
Oct...
Dec...
Oct...
Nov...
Dec...
Jan
April..
Oct...
Nov...
Dec...
Oct...
Jan
April..
Sept...
Nov...
Dec...
Dec...
Dec...
Jan
Dec...
Year of release
1952
76
38
7
71
46
1.56
67
1156
1953
14
60
472
12
1964
1954
4
7
21
11
147
10
5
125
148
5
12
33
11
151
295
22
76
48
4
331
41
81
9
2195
1955
16
11
4
13
41
11
118
2356
1956
581
1957
1958
19.59
14
48
24
46
36
84
22
3
43
2745
19
89
43
44
81
10
75
24
2110
106
866
CALIFORNIA PISH AND GAME
APPENDIX D
Number of Skipjack Tagged and Released by Area
(One-Degree Square), Month and Year
One-degree
square
Moiitli
of
release
Year of release
1952
1953
1954
1955
1956
1957
1958
1959
30N-119W__-
Sept
28N-115W_--
Aug
28N-116\V__J
Aug
28N-121W.__
Aug
27N-114W_._
July
27N-114W__
Aug
27N-114W__-
Oct
27N-115W___
Sept
27N-115W__
Oct
27N-I20W_ _
Aug
26N-113W__ .
June
26N-113W.
Aug
26N-113W_ _
Oct
26N-114W_
July
26N-114\V_ .
Aug
26N-115W___
Oct
25N-1I2\V___
June
25N-112W__.
July
25N-113W__
July
25N-113W___
Aug
25N-113\V__.
Sept
25N-113W___
Oct
24N-111W_--
May
24N-112W___
June
24N-112W___
July
24N-112VV__-
Sept
24N-115W..-
July
23N-109W___
Nov
23N-111W_-.
May
23N-111\V___
June
23N-111W__.
July
23N-111W_^_
Sept
23N-112W___
May
23N-112W___
June
23N-112\V__
July
23N-113W_._
July
22N-106W_^_
Nov
22N-106W__
Dec
22N-108\V_-_
Feb
22N-110\V_..
June
22N-niW___
June
22N-111W___
July
22N-112W^._
June
22N-n2\V\__
July
22N-113W___
Julv
21N-105\V__^
Nov
21N-106W___
May
21N-10(5W__
June
21N-106\V^__
Nov
21N-106W___
Dec
21N-110\V_^.
June
21N-111\V„^_
June
20N-105\V__.
Nov
20N-106W__
June
20N-106W_^^
Nov
19N-106W.__
April
19N-110W__,
April
19N-111V\\.^
July
19N-111W_.
Aug
19N-112W__^
May
19N-112W___
July
19N-112W_._
Aug
18N-105W._.
April
40
1
24
17
23
43
105
68
123
69
70
39
88
21
67
50
3
169
1
70
216
18
49
17
6
62
237
99
275
2
46
14
2
82
180
37
33
9
12
11
3
119
9
207
457
24
9
18
73
273
53
49
30
16
123
14
111
TUNA TAGGING
867
APPENDIX D-Continued
Number of Skipjack Tagged and Released by Area
(One-Degree Square), Month and Year
Year of release
]\Iontli
of
One-degree
square
release
1952
1953
1954
1955
1956
1957
1958
1959
18N-105W,__
May
4
18N-106W^__
April
38
18N-107W_._
April
1
ISN-llOW...
May
3
18N-111W___
July
196
18N-111W___
Aug
125
18N-111W__-
Sept
1
18N-112W___
July
73
18N-112W___
Aug
70
18N-114W__^
May
7
18N-114W.--
June
4
12
17N-101W__.
Nov
1
17N-103W___
May
2
5
17N-104W_.
April
2
16N-100W__
May
29
16N-101"W\-_
April
4
16N-101W___
May
21
17
lf5N-102W__.
March
13
lGN-102W_-_
April
8
U)N-102W_..
May
4
16N-103W___
April
3
16N-103W^__
May
9
15N-97W
March
8
15N-98W
April
1
15N-100W._.
April
1
15N-101W_._
March- __
11
15N-101W___
April
34
15N-101W___
May
18
15N-102W__
May
13
1.5N-106W_^
Feb
7
14N-94W
April
18
13N-89W
April
9
13N-90W
Feb
2
13N-90W
March
12
13N-91W
March
5
13N-95W
April
45
13N-96W
April
10
13N-97W_.__
Feb
1
13N-101W_„^
Feb
2
12N-87W
May
0
12N-87W____
Sept
73
12N-88W
May
1
12N-88W
Oct
18
12N-89W
March
1
12N-89W
April
6
12N-90W
March. _.
36
12N-91W
Feb
7
12N-91W
April
1
12N-92W
Feb
37
12N-93W
Feb
5
8
12N-93W
March
9
11N-87W
April
52
11N-87W
Sept
41
11N-87W
Oct
33
11N-88W
Oct
13
11N-92W
Feb
10
11N-93W
Feb
12
10N-85W
Sept
25
10N-86W
Jan
26
10N-86W
Feb
1
1
10N-86W
March
16
4
10N-86W
April
12
10N-86W
May
17
119
368
CALIFORNIA FISH AND GAME
APPENDIX D-Continued
Number of Skipjack Tagged and Released by Area
(One-Degree Square), Month and Year
One-degree
square
Montli
of
release
Year of release
1952
1953
1954
1955
1956
1957
1958
1959
]0N-86W.__
10N-86W_..
10N-91W___
10N-109W.-
09N-84W __
09N-85W.__
09N-85W„_-
09N-85W___
08N-83W___
08N-83W._-
08N-83W_.-
08N-84W__
08N-85W,__
08N-85W___
07N-78W__
07N-79W_^_
07N-81W__^
07N-82W_„_
07N-82W__-
07N-82W
07N-83W___
07N-83W___
07N-84W
07N-84W
07N-85W___.
07N-86W
07N-88W__..
06N-77W___.
06N-77W
06N-78W
06N-79W
06N-83W
06N-83W
06N-84W
06N-85W_ _ _ .
06N-86W
05N-77W
05N-77W
05N-77W
05N-80W
05N-82W
05N-86W
05N-88W
04N-88W
05N-78W
04N-80W
04N-81W
03N-78W
03N-81W
03N-90W
02N-78W
02N-78W
02N-79W
02N-79W
02N-79W
02N-79W
02N-91W
02N-91W
01N-79W
01N-79W
01N-79W
01N-79W
01N-90W
July__.
Oct
May-_-
Oct
May_._
Feb
April
Sept
Feb
Oct
Nov....
Oct
March.
April...
June
Feb....
Jan
Jan
Feb
July
Jan
March. .
Feb
March..
March..
March. .
Oct
Jan
June
March..
July
Jan
June
March..
March..
March. .
Feb
March,.
June
July
June
Jan
Feb
March-.
June
July
June
Feb
March. -
March,.
Jan
May
Jan
Feb
May
Dec
March. .
Sept
Jan
Feb
May
Dec...
March. •
42
3
25
50
11
55
1
20
13
23
10
10
24
20
10
3
6
11
3
21
112
15
10
2
58
17
3fi
23
4
1
92
03
3
12
27
2
6
20
1
2
1
2
2
10
TUNA TAGGING
369
APPENDIX D-Continued
Number of Skipjack Tagged and Released by Area
(One-Degree Square), Month and Year
One-degree
square
Month
of
release
Year of release
1952
1953
1954
1955
1956
1957
1958
1959
01N-91W-.
01N-91W..
OlN-91W-_
01N-91W_.
01N-91W_.
01N-92W.^
()1N-92W__
00N-80W__
00N-89W-.
00N-90W--
00N-90W_.
00N-91W_.
00N-91W_.
00N-91W--
00S-80W._.
00S-80W_..
00S-80W._.
00S-89W_..
00S-89W._
00S-90W__
00S-91W._
00S-91W..
00S-91W_.
01S-81W..
01S-81W..
01S-81W..
01S-81W._
01S-81W_.
01S-81W_.
01S-89W__
01S-90W_.
01S-91W._
01S-91W_-
02S-81W.,
02S-81W,-
02S-81W..
02S-81W._
03S-80W-_
03S-80W..
03S-80W__
03S-81W.„
03S-81W,_
03S-81W__
03S-81W._
03S-81W._
03S-81W._
04S-81W_.
04S-81W..
08S-80W_.
08S-80W..
09S-79W_.
09S-79W_.
09S-79W__
09S-79W.,
09S-79W_.
09S-80W_.
09S-80W_
11S-78W_
19S-70W_
20S-70W.
20S-70W.
Feb
March
Sept
Nov
Dec
March
Dec
Jan
Feb
March
Nov
Feb
March___
Nov
Jan
March
June
March.. _
Dec
Nov
March
April
Nov
Jan
May
June
July
Nov
Dec
Nov
March
Feb
March
May
July
Oct
Dec
Oct
Nov
Dec
Jan
Feb
April
Oct
Nov
Dec
Feb
Oct
April
Sept
Jan
April
Sept
Nov
Deo
Sept
Dec
Jan
Dec
Jan
Dec
17
43
62
11
29
22
Totals-
74
47
76
509
831
11
105
7
81
14
70
146
1
193
116
370
1
79
107
76
89
31
515
114
44
292
31
3266
173
174
20
38
278
3
156
270
23
42
1010
39
94
2311
53
32
142
327
1474
95
110
3
95
14
244
8
69
646
83
27
2
45
3401
14
106
1331
1463
NOTE
Toxicity of Tricon Oil Spill Erodicator to Striped Bass
fRoccus saxafilis)
Tricon Oil Spill Eradieator is a commercial product designed to
emulsify oil spilled on water. Tlie manufacturer lists the composition
as 20 percent petroleum sulfonate, 5 percent fatty acid esters, 10 ix-r-
cent polyethylene glycol ether, 68 percent petroleum solvents, and 2
percent alcohol.
The use of Tricon Oil Spill Eradieator has been proposed in waters
of the San Francisco Bay area. Since these waters are inhabited by
striped bass, the California Department of Fish and Game conducted
bioassays in early 1957, in order to determine this eradieator 's toxicity
to this species.
Five striped bass were placed in each of eight aquaria containing
7,500 ml. of a mixture of water taken from the San Joacpiin Kiver
at Antioch and various amounts of oil spill eradieator. For a control,
five bass were placed in a ninth aquarium with 7,500 ml. of river
v\'ater. The bass used ranged from 2.7 to 4.3 inches and averaged 3.4
inches in fork length. Air was bubbled slowly througli the watci- in
;ill aquaria; water temperature was maintained at apj)roximately 65
degrees F.
The resultiS were as follows :
Percentage
concentration
Survival
of Tricon
Oil Spill
Eradieator
Elapsed
time
Number of
bass alive
Remarks
2.0
7 minutes
0
All fish showed immediate distress.
0.1
6 minutes
0
All fish showed immediate distress.
0.05 -
8 minutes
0
All fish showed immediate distress.
0.005 - - ---
30 minutes
1 hour
2
0
All fish showed distress after about one
minute.
0.0016
1 hour
2 hours
3 hours
4 hours
5 hours
5
3
2
1
0
Fish started showing irritation after
several minutes.
0.001
4 hours
5 hours
6 hours
8 hours
9 hours
10 hours
5
3
2
2
1
0
Fish showed first signs of distress at 1 V^
hours.
0.0005 ^
48 hours
5
Fish showed no distress.
0.0005 -
48 hours
5
Fish showed no distress.
Control
48 hours
5
Fish showed no distress.
(371)
372 CALIFORNIA FISH AND GAME
These results sliow clearly that Tricon Oil Spill Eradieator is toxic
to striped bass at low concentrations. It is probable that lethal con-
centrations would Occur at least locally, if the eradieator were used
to treat oil spills. — Harold K. CJiadwick, Californid Dept. of Fish and
Game, January, 1960.
NOTE
A Range Extension of the California Halibut
(Parolichthys californicus)
On Xoveinber 10 or 11, 1959, Mr. Jim Riley, skipper of the trawler
IN A, was fishing for English sole (Parophrys vefidus) and petrale
sole (Eopsetia jordani) in 30 to 35 fathoms of water four to six miles
north of Redding Rock. While sorting liis eatch, he discovered a fish
he believed was a California halibnt. He turned it over to me and
asked me to verify his identification.
It was taken to Eureka Marine Resources Laboratory where positive
identification was made (counts and measurements are listed in Table
1). This proved a substantial northerly extension of the previous known
range, Tomales Bay (Roedel, 1953).
TABLE 1
Meristic Counts and Measurements From a Left-eyed Paralichfhys californicus Taken Off
Redding Rocl<, November 1959
Measurements :*
Standard length 370 . 0
Total length 116.2
Head length 19.9
Snout length 5.7
Orbit width 2.7
Maxillary length 10.5
Body depth 41.1
Counts:
Dorsal rays 72
Anal rays 56
Ventral rays : right 6
left -. 6
Pectoral rays : right 12
left 12
Principal caudal rays 17
Gill rakers : lower limb 20
upper limb 9
* Standard lengtli given in millinii'tci-s; all other mpasiiicmciits presented as pci-eenfaKPS of staiidaifl leiiclli.
A California halibut was reported from this area on Januaiy 23,
1952, when a fish and game warden told biologist R. B. McCormick
one had been caught by the trawler DOliOTlIY AXX off the mouth of
the Klamath River. This was confirmed by Ray Hamblock, manager
of the Balesteri Fish Company. He stated that the fish weighed 24
pounds. It was no longer available so McCormick could not make a
positive identification.
On August 30, 1954, while making a sportfish survey at Buhne's
Point (Humboldt Bay), McCormick recorded a California halibut that
( 373 )
31i CAUFOENIA FIBH ASD GAME
liad been taken by a BportKiaan wlule drift fishijig for salmon at the
moutb of the bar. Positive identifieatioB -wa*; made bj MeCormiek.
MeaKurementK and fin coiint« -wrere taken^ but iinfortimatejT tM« in-
formation wa« loKt ri"--'_r a move, ""i '^'. - -f' ■'i - -f' i - m file at tli€
Eureka laboratory jj ■• it wan aj ^ . _ - long.
On AugTiKt 15, 1959, biologist Dan (jotsbaU was ijiform-ed by a sports-
fisherman that a California halibut had been taken at Shelter CoT-e
(Humboldt County). GotshaU contacted tbe fishermen fKalph L.
Reese), but the fish was not arailable so Mr. E.eese sent photos to sub-
stantiate the Talidity of the report.
REFERENCE
Koedel, Phi] M.
1953. CommoD ocean fishes of the CaliforuLia eoa«t. Calif. I>ept. Fi«h and 'Gaine,
Fish Bun. 91, 184 pp., 175 fig«.
E. <?. 'Cht.nderson, Marine Eenowroes •Operations, 'California Depuriineni of Fish
and Ganoe, Janua/ry, 1960.
REVIEWS
Oceanography and Marine B'.ology
By II. I'.ai'iics; The M;icinillaii (\... New York. I!).".'.! ; 21S pp.. I HI li-s. :•,.". sliillinns.
This is a l)(H)k of l<H'hiii(HU's. It is (k'siiiucil to inforiu the i-cadcr liow l^iiow led;;!'
of the sea and of some of its iiihahitaiits is ohtaiiu'd. It is wfitti'ii in ,i siinpif
straightforward style inakinj;- it easy for a li('?;iiinci- to dcridr wliai insi rnnifuls
lua.v best suit his needs.
.\ primary coiieerii is witii liic prolilcnis imnlxcd in iiiai^iiii;' oliscr\ al ions and
ineasui'ements in the oeean. Tliis is one of the few times that the scattered accounts
of etiuipment and techni(pH's used in oceanojiraphy au<l uuirine hiolo<;y have hccu
assemiiled under one co\'er — this ah>ne makes the booli a welcome addilion In
tin' literature.
A hook of this sco|)e necessarily involves faii'ly detailed descriptions of f;'eai'
and methods; suiijects that ordinarily make dull readinj;- for all except the
professional worker. l>r. Barnes sm-eeeds in holding; the reader's interest, however,
by frequently insert ini; into the gear descriptions discussions of applications, results,
and limitations; and by the lil)(»ral use of drawings and photographs.
It resendiles a hamlbook and is divided into four nni.jor sections: the tirsi deals
with nu'thods and gear used for sampling living pidagic organisms, except fish,
and those that live on and within the ocean bottom sedinu'uts; the second section
describes the use of shijjboard sound waves in relation to lisheries, and includes
a disc'ussi(ni of umlerwater noises pi'oduced by \ai-ious sitecies of lish ; the third is
concerned with proi)erties of the water itself, but is limited to temperalnre, -alinity,
and current measnrments ; and the l.-ist section rel.-ites both aerial and underwalei-
photogra]ih.\- to tisheri<>s problems.
Dr. r.arnes also has included nine pages of ret'eienees. which will piove of con-
siderable v;ilue to anyone interested in oceanography and marine bi(dogy t eelin iipu's.
— JTdidhJ II. Clciiifiis. CdHfuriiid I hp<i rhiicii t (if Fisli diiil fhniir.
Nafural Resources
By INIartin K. Iluberty ami Warren L. Flock; IMcGra w 1 lill Book Company. Inc.,
New York. I'.ir.'.l; xviii -t- nr.n p])., $11.
This book was wi'itten as a textbook in natni-al resoni'ces study for use by
engineering students at the university level. As snch, it compiles within its ."."it; pages
a tremendous wealth of knowledge and |irof(Min(l thought regarding both nnr renew-
al)le and nonrenewable resources.
Leading authorities have eadi wi-itten dnipters covering their respective lields.
l^xamples are: Marine Resources. MiliH'r Sdmefer ami Roger Heville ; Ecolog.v and
Wildlife, Walter P. Taylor; ami Forest Land and Forest Products, John .\.
Zivnuska.
The chapter on marine resources is of especial interest to biidogists. All uses of
the ocean environnu-nt are considered from recreation and waste disjjo.sal to water
supply. Emphasis is placed <m the fact^ that we currently harvest oidy a small
fraction of the organic production of the sea.
"The challenge of new fields to cinnpuM- is clearly shown when we consider that
the ma.jor fisheries are for the same kiml of organisms that ha\e been exploited since
man first went to sea, that is, those whose aggregation habits make Ibeni amenable
to lai-ge scale capture by the tradition.-il kinds of gear."
Regarding human consumption of marine food pnxlucts, it was surprising to learn
that in the United States it has not in<re,ised <ni a pei- c.ipita basis during the i)ast
20 years despite improved refrigeration, transportation ami retail marketing facili-
ties. (%'i-tain specific marine food items ha\'e increased, bni ,it the exjiense of others.
The author does not anticipate the use of lower levids of the marine food chain to
be economically pidtitable for many years. A similar prognostication is made for
farming the sea in a manner analogous to agriculture excepi for the shellfish.
(375)
376 CALIFORNIA FISH AND GAME
Many sage comments are fniiiul throughout the book sut-h as this one: "There is
a vory groat ueetl for thorough studies, coniluuing ecoiuuuios and the natural sciences
of marine resources in (•r(h'r In (h'vtdop a ni()re rational hasis for their exploitation."
Other chapters ar(> eiiually informative. The biologist as well as the physical
scientist will find this volume most useful as a means of broadening his background
informal ii)n on our natural resources and their uses. It will serve also as a handy
reference. — Willis A. Kraiis. ('(ilifurnin T)r]iiirl mi ul of Fish (i)iil (liniiV.
prhileJ ill caiitornm STATn PRiNTiNfi oi'fice
17250 4-00 5,200
1
Live Music
Archive
Librivox
Free Audio
Metropolitan Museum
Cleveland
Museum of Art
Internet
Arcade
Console Living Room
Open Library
American
Libraries
TV News
Understanding
9/11